Android 开源框架之 Android-async-http 源码解读
2016-10-08 15:44
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开源项目链接
Android-async-http仓库：https://github.com/loopj/android-async-httpandroid-async-http主页：http://loopj.com/android-async-http/（估计需要翻墙）
开源项目简介
该框架是基于Apache HttpClient API 用于Android开发的一个异步并发的网络请求库，所以的网络请求都是在非UI线程中执行，请求的结果都是通过接口回调，利用Android的Handler+Message机制来从非UI线程中获得。
开源框架的主要常用特征
1.支持HTTP网络异步请求，通过接口回调获得请求结果。 2.HTTP请求全部发生在非UI线程中。 3.使用线程池（ThreadPool）并发请求支援。 4.支持GET/POST 参数请求（RequestParams：封装参数类）。 5.无需第三方lib，支持上传文件。 6.支持网络自动连接，网络断开重连机制。 7.支持关联Activity生命周期取消网络请求。
开源框架使用实例
<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">AsyncHttpClient client = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> AsyncHttpClient();
client.get(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"http://www.baidu.com"</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> AsyncHttpResponseHandler() {
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onStart</span>() {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// called before request is started</span>
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onSuccess</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> statusCode, Header[] headers, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">byte</span>[] response) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// called when response HTTP status is "200 OK"</span>
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onFailure</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> statusCode, Header[] headers, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">byte</span>[] errorResponse, Throwable e) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// called when response HTTP status is "4XX" (eg. 401, 403, 404)</span>
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onRetry</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> retryNo) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// called when request is retried</span>
}
});</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li></ul>不过在一个完整的项目中官网不建议以上的使用方式，官网建议创建一个 static 的 HttpClient，如下：
<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> TwitterRestClient {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> final String BASE_URL = <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"http://api.twitter.com/1/"</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> AsyncHttpClient client = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> AsyncHttpClient();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">get</span>(String url, RequestParams <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span>, AsyncHttpResponseHandler responseHandler) {
client.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">get</span>(getAbsoluteUrl(url), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span>, responseHandler);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">post</span>(String url, RequestParams <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span>, AsyncHttpResponseHandler responseHandler) {
client.post(getAbsoluteUrl(url), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span>, responseHandler);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> String <span class="hljs-title" style="box-sizing: border-box;">getAbsoluteUrl</span>(String relativeUrl) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> BASE_URL + relativeUrl;
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li></ul>然后在客户端很简单的使用上面的方法，代码如下：
<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">class TwitterRestClientUsage {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">getPublicTimeline</span>() throws JSONException {
TwitterRestClient.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">get</span>(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"statuses/public_timeline.json"</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> JsonHttpResponseHandler() {
@Override
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onSuccess</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> statusCode, Header[] headers, JSONObject response) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// If the response is JSONObject instead of expected JSONArray</span>
}
@Override
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onSuccess</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> statusCode, Header[] headers, JSONArray timeline) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Pull out the first event on the public timeline</span>
JSONObject firstEvent = timeline.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">get</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>);
String tweetText = firstEvent.getString(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"text"</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Do something with the response</span>
System.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">out</span>.println(tweetText);
}
});
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li></ul>这样就免去了多次网络请求创建多个HttpClient实例了。
带参数的POST请求
该框架支持带参数网络请求，使用参数封装类RequestParams。代码示例：
<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">class TwitterRestClientUsage {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//普通参数封装</span>
RequestParams <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span> = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> RequestParams();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span>.put(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"key"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"value"</span>);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span>.put(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"more"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"data"</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//上传文件参数封装</span>
File myFile = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> File(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"/path/to/file.png"</span>);
RequestParams <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span> = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> RequestParams();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span>.put(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"profile_picture"</span>, myFile);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span>(FileNotFoundException e) {}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//上传流参数封装</span>
InputStream myInputStream = blah;
RequestParams <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span> = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> RequestParams();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span>.put(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"secret_passwords"</span>, myInputStream, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"passwords.txt"</span>);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">getPublicTimeline</span>() throws JSONException {
TwitterRestClient.post(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"statuses/public_timeline.json"</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">params</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> JsonHttpResponseHandler() {
@Override
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onSuccess</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> statusCode, Header[] headers, JSONObject response) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// If the response is JSONObject instead of expected JSONArray</span>
}
@Override
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onSuccess</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> statusCode, Header[] headers, JSONArray timeline) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Pull out the first event on the public timeline</span>
JSONObject firstEvent = timeline.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">get</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>);
String tweetText = firstEvent.getString(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"text"</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Do something with the response</span>
System.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">out</span>.println(tweetText);
}
});
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li></ul>
源码解读框架请求的原理
1.从实例化对象开始
<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Creates a new AsyncHttpClient with default constructor arguments values
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">AsyncHttpClient</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">false</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">80</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">443</span>);
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
*所有的构造方法最后都跳转到这里，三个参数的含义如下
* Creates new AsyncHttpClient using given params
*
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> fixNoHttpResponseException 是否添加SSL安全验证？默认的是false
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> httpPort HTTP 端口，默认80
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> httpsPort HTTPS 端口，默认443
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">AsyncHttpClient</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> fixNoHttpResponseException, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> httpPort, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> httpsPort) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>(getDefaultSchemeRegistry(fixNoHttpResponseException, httpPort, httpsPort));
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Creates a new AsyncHttpClient.
* 这个构造方法中配置网络请求参数，比如链接超时，最大连接数，线程池创建，网络重连机制等
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> schemeRegistry SchemeRegistry to be used
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">AsyncHttpClient</span>(SchemeRegistry schemeRegistry) {
BasicHttpParams httpParams = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BasicHttpParams();
ConnManagerParams.setTimeout(httpParams, connectTimeout);
ConnManagerParams.setMaxConnectionsPerRoute(httpParams, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> ConnPerRouteBean(maxConnections));
ConnManagerParams.setMaxTotalConnections(httpParams, DEFAULT_MAX_CONNECTIONS);
HttpConnectionParams.setSoTimeout(httpParams, responseTimeout);
HttpConnectionParams.setConnectionTimeout(httpParams, connectTimeout);
HttpConnectionParams.setTcpNoDelay(httpParams, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
HttpConnectionParams.setSocketBufferSize(httpParams, DEFAULT_SOCKET_BUFFER_SIZE);
HttpProtocolParams.setVersion(httpParams, HttpVersion.HTTP_1_1);
ClientConnectionManager cm = createConnectionManager(schemeRegistry, httpParams);
Utils.asserts(cm != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Custom implementation of #createConnectionManager(SchemeRegistry, BasicHttpParams) returned null"</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//执行网络请求的线程池，从代码看，这是一个并发请求的线程池。</span>
threadPool = getDefaultThreadPool();
requestMap = Collections.synchronizedMap(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> WeakHashMap<Context, List<RequestHandle>>());
clientHeaderMap = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> HashMap<String, String>();
httpContext = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> SyncBasicHttpContext(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BasicHttpContext());
httpClient = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> DefaultHttpClient(cm, httpParams);
httpClient.addRequestInterceptor(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> HttpRequestInterceptor() {
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">process</span>(HttpRequest request, HttpContext context) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!request.containsHeader(HEADER_ACCEPT_ENCODING)) {
request.addHeader(HEADER_ACCEPT_ENCODING, ENCODING_GZIP);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (String header : clientHeaderMap.keySet()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (request.containsHeader(header)) {
Header overwritten = request.getFirstHeader(header);
Log.d(LOG_TAG,
String.format(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Headers were overwritten! (%s | %s) overwrites (%s | %s)"</span>,
header, clientHeaderMap.get(header),
overwritten.getName(), overwritten.getValue())
);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//remove the overwritten header</span>
request.removeHeader(overwritten);
}
request.addHeader(header, clientHeaderMap.get(header));
}
}
});
httpClient.addResponseInterceptor(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> HttpResponseInterceptor() {
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">process</span>(HttpResponse response, HttpContext context) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> HttpEntity entity = response.getEntity();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (entity == <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> Header encoding = entity.getContentEncoding();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (encoding != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (HeaderElement element : encoding.getElements()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (element.getName().equalsIgnoreCase(ENCODING_GZIP)) {
response.setEntity(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> InflatingEntity(entity));
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
}
}
}
}
});
httpClient.addRequestInterceptor(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> HttpRequestInterceptor() {
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">process</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> HttpRequest request, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> HttpContext context) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> HttpException, IOException {
AuthState authState = (AuthState) context.getAttribute(ClientContext.TARGET_AUTH_STATE);
CredentialsProvider credsProvider = (CredentialsProvider) context.getAttribute(
ClientContext.CREDS_PROVIDER);
HttpHost targetHost = (HttpHost) context.getAttribute(ExecutionContext.HTTP_TARGET_HOST);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (authState.getAuthScheme() == <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
AuthScope authScope = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> AuthScope(targetHost.getHostName(), targetHost.getPort());
Credentials creds = credsProvider.getCredentials(authScope);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (creds != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
authState.setAuthScheme(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BasicScheme());
authState.setCredentials(creds);
}
}
}
}, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//网络出错重连机制</span>
httpClient.setHttpRequestRetryHandler(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> RetryHandler(DEFAULT_MAX_RETRIES, DEFAULT_RETRY_SLEEP_TIME_MILLIS));
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li><li style="box-sizing: border-box; padding: 0px 5px;">69</li><li style="box-sizing: border-box; padding: 0px 5px;">70</li><li style="box-sizing: border-box; padding: 0px 5px;">71</li><li style="box-sizing: border-box; padding: 0px 5px;">72</li><li style="box-sizing: border-box; padding: 0px 5px;">73</li><li style="box-sizing: border-box; padding: 0px 5px;">74</li><li style="box-sizing: border-box; padding: 0px 5px;">75</li><li style="box-sizing: border-box; padding: 0px 5px;">76</li><li style="box-sizing: border-box; padding: 0px 5px;">77</li><li style="box-sizing: border-box; padding: 0px 5px;">78</li><li style="box-sizing: border-box; padding: 0px 5px;">79</li><li style="box-sizing: border-box; padding: 0px 5px;">80</li><li style="box-sizing: border-box; padding: 0px 5px;">81</li><li style="box-sizing: border-box; padding: 0px 5px;">82</li><li style="box-sizing: border-box; padding: 0px 5px;">83</li><li style="box-sizing: border-box; padding: 0px 5px;">84</li><li style="box-sizing: border-box; padding: 0px 5px;">85</li><li style="box-sizing: border-box; padding: 0px 5px;">86</li><li style="box-sizing: border-box; padding: 0px 5px;">87</li><li style="box-sizing: border-box; padding: 0px 5px;">88</li><li style="box-sizing: border-box; padding: 0px 5px;">89</li><li style="box-sizing: border-box; padding: 0px 5px;">90</li><li style="box-sizing: border-box; padding: 0px 5px;">91</li><li style="box-sizing: border-box; padding: 0px 5px;">92</li><li style="box-sizing: border-box; padding: 0px 5px;">93</li><li style="box-sizing: border-box; padding: 0px 5px;">94</li><li style="box-sizing: border-box; padding: 0px 5px;">95</li><li style="box-sizing: border-box; padding: 0px 5px;">96</li><li style="box-sizing: border-box; padding: 0px 5px;">97</li><li style="box-sizing: border-box; padding: 0px 5px;">98</li><li style="box-sizing: border-box; padding: 0px 5px;">99</li><li style="box-sizing: border-box; padding: 0px 5px;">100</li><li style="box-sizing: border-box; padding: 0px 5px;">101</li><li style="box-sizing: border-box; padding: 0px 5px;">102</li><li style="box-sizing: border-box; padding: 0px 5px;">103</li><li style="box-sizing: border-box; padding: 0px 5px;">104</li><li style="box-sizing: border-box; padding: 0px 5px;">105</li><li style="box-sizing: border-box; padding: 0px 5px;">106</li><li style="box-sizing: border-box; padding: 0px 5px;">107</li><li style="box-sizing: border-box; padding: 0px 5px;">108</li><li style="box-sizing: border-box; padding: 0px 5px;">109</li><li style="box-sizing: border-box; padding: 0px 5px;">110</li><li style="box-sizing: border-box; padding: 0px 5px;">111</li><li style="box-sizing: border-box; padding: 0px 5px;">112</li><li style="box-sizing: border-box; padding: 0px 5px;">113</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li><li style="box-sizing: border-box; padding: 0px 5px;">69</li><li style="box-sizing: border-box; padding: 0px 5px;">70</li><li style="box-sizing: border-box; padding: 0px 5px;">71</li><li style="box-sizing: border-box; padding: 0px 5px;">72</li><li style="box-sizing: border-box; padding: 0px 5px;">73</li><li style="box-sizing: border-box; padding: 0px 5px;">74</li><li style="box-sizing: border-box; padding: 0px 5px;">75</li><li style="box-sizing: border-box; padding: 0px 5px;">76</li><li style="box-sizing: border-box; padding: 0px 5px;">77</li><li style="box-sizing: border-box; padding: 0px 5px;">78</li><li style="box-sizing: border-box; padding: 0px 5px;">79</li><li style="box-sizing: border-box; padding: 0px 5px;">80</li><li style="box-sizing: border-box; padding: 0px 5px;">81</li><li style="box-sizing: border-box; padding: 0px 5px;">82</li><li style="box-sizing: border-box; padding: 0px 5px;">83</li><li style="box-sizing: border-box; padding: 0px 5px;">84</li><li style="box-sizing: border-box; padding: 0px 5px;">85</li><li style="box-sizing: border-box; padding: 0px 5px;">86</li><li style="box-sizing: border-box; padding: 0px 5px;">87</li><li style="box-sizing: border-box; padding: 0px 5px;">88</li><li style="box-sizing: border-box; padding: 0px 5px;">89</li><li style="box-sizing: border-box; padding: 0px 5px;">90</li><li style="box-sizing: border-box; padding: 0px 5px;">91</li><li style="box-sizing: border-box; padding: 0px 5px;">92</li><li style="box-sizing: border-box; padding: 0px 5px;">93</li><li style="box-sizing: border-box; padding: 0px 5px;">94</li><li style="box-sizing: border-box; padding: 0px 5px;">95</li><li style="box-sizing: border-box; padding: 0px 5px;">96</li><li style="box-sizing: border-box; padding: 0px 5px;">97</li><li style="box-sizing: border-box; padding: 0px 5px;">98</li><li style="box-sizing: border-box; padding: 0px 5px;">99</li><li style="box-sizing: border-box; padding: 0px 5px;">100</li><li style="box-sizing: border-box; padding: 0px 5px;">101</li><li style="box-sizing: border-box; padding: 0px 5px;">102</li><li style="box-sizing: border-box; padding: 0px 5px;">103</li><li style="box-sizing: border-box; padding: 0px 5px;">104</li><li style="box-sizing: border-box; padding: 0px 5px;">105</li><li style="box-sizing: border-box; padding: 0px 5px;">106</li><li style="box-sizing: border-box; padding: 0px 5px;">107</li><li style="box-sizing: border-box; padding: 0px 5px;">108</li><li style="box-sizing: border-box; padding: 0px 5px;">109</li><li style="box-sizing: border-box; padding: 0px 5px;">110</li><li style="box-sizing: border-box; padding: 0px 5px;">111</li><li style="box-sizing: border-box; padding: 0px 5px;">112</li><li style="box-sizing: border-box; padding: 0px 5px;">113</li></ul>2.GET/POST网络请求
由源码看出，所有的网络请求都会跳转到这个方法 sendRequest();，我们进入代码世界看看它里面都干了些啥？
<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> RequestHandle <span class="hljs-title" style="box-sizing: border-box;">sendRequest</span>(DefaultHttpClient client, HttpContext httpContext, HttpUriRequest uriRequest, String contentType, ResponseHandlerInterface responseHandler, Context context) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//代码写的很严谨，判断参数是否有效，值得学习。</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (uriRequest == <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throw</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> IllegalArgumentException(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"HttpUriRequest must not be null"</span>);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (responseHandler == <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throw</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> IllegalArgumentException(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"ResponseHandler must not be null"</span>);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (responseHandler.getUseSynchronousMode() && !responseHandler.getUsePoolThread()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throw</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> IllegalArgumentException(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Synchronous ResponseHandler used in AsyncHttpClient. You should create your response handler in a looper thread or use SyncHttpClient instead."</span>);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (contentType != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (uriRequest <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">instanceof</span> HttpEntityEnclosingRequestBase && ((HttpEntityEnclosingRequestBase) uriRequest).getEntity() != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
Log.w(LOG_TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Passed contentType will be ignored because HttpEntity sets content type"</span>);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
uriRequest.setHeader(HEADER_CONTENT_TYPE, contentType);
}
}
responseHandler.setRequestHeaders(uriRequest.getAllHeaders());
responseHandler.setRequestURI(uriRequest.getURI());
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//创建一个异步网络请求AsyncHttpRequest类实例，这个类继承自Runnable，实现了run（）方法。</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//方法里面是真正的网络请求数据的过程，内具怎么做呢？等下我们去看看。</span>
AsyncHttpRequest request = newAsyncHttpRequest(client, httpContext, uriRequest, contentType, responseHandler, context);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//重点啊，异步网络请求线程被提交给线程池，让线程池来实现网络的并发请求。</span>
threadPool.submit(request);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//网络请求控制类，用于客户端取消正在执行的网络请求。</span>
RequestHandle requestHandle = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> RequestHandle(request);
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**只有当AsyncHttpClient与Activity关联起来了才保存网络请求requestHandle
用于客户端控制网络的请求
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (context != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
List<RequestHandle> requestList;
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Add request to request map</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">synchronized</span> (requestMap) {
requestList = requestMap.get(context);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (requestList == <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
requestList = Collections.synchronizedList(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> LinkedList<RequestHandle>());
requestMap.put(context, requestList);
}
}
requestList.add(requestHandle);
Iterator<RequestHandle> iterator = requestList.iterator();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span> (iterator.hasNext()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (iterator.next().shouldBeGarbageCollected()) {
iterator.remove();
}
}
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> requestHandle;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li></ul>3.AsyncHttpRequest的实现
真正执行网络请求的地方是 AsyncHttpRequest类，该类继承自 Runnable接口，实现线程的run()方法。
内部具体怎么实现的，我们进去看看run（）方法的代码：
<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">run</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (isCancelled()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Carry out pre-processing for this request only once.</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!isRequestPreProcessed) {
isRequestPreProcessed = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**执行网络请求前的准备操作，默认是个空方法，
如果客户需要在执行网络请求前做一些准备工作，且很耗时的话，可以在外部重写这个空方法。
*/</span>
onPreProcessRequest(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (isCancelled()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/*responseHandler ：ResponseHandlerInterface接口的实例，用于接收网络请求结果。具体实现
等会一一分析。这里通过ResponseHandlerInterface接口回调告诉UI线程，网络请求线程开始网络请求
了。
*/</span>
responseHandler.sendStartMessage();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (isCancelled()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
这里是真正执行网络请求的入口。
*/</span>
makeRequestWithRetries();
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (IOException e) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!isCancelled()) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//如果网络请求异常，将失败结果通过ResponseHandlerInterface接口回调告诉UI线程。</span>
responseHandler.sendFailureMessage(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>, e);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
Log.e(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"AsyncHttpRequest"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"makeRequestWithRetries returned error"</span>, e);
}
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (isCancelled()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//这里通过ResponseHandlerInterface接口回调告诉UI线程，网络请求线程结束网络请求。</span>
responseHandler.sendFinishMessage();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (isCancelled()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Carry out post-processing for this request.</span>
onPostProcessRequest(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//标志网络请求完成。</span>
isFinished = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
}
.............................
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//真正的网络请求，其中省略很多代码，直接看重点就是makeRequest()方法了。</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">makeRequestWithRetries</span>() <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> IOException {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> retry = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
IOException cause = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>;
HttpRequestRetryHandler retryHandler = client.getHttpRequestRetryHandler();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
.....................
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span> (retry) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
makeRequest();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
....................
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">makeRequest</span>() <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> IOException {
...............................
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (responseHandler <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">instanceof</span> RangeFileAsyncHttpResponseHandler) {
((RangeFileAsyncHttpResponseHandler) responseHandler).updateRequestHeaders(request);
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//终于到了，唉，是不是感觉有点熟悉，网络请求获得结果。</span>
HttpResponse response = client.execute(request, context);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (isCancelled()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Carry out pre-processing for this response.</span>
responseHandler.onPreProcessResponse(responseHandler, response);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (isCancelled()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// The response is ready, handle it.</span>
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**网络请求通过ResponseHandlerInterface接口回调将请求的结果拿到。
那么到这里，我们是不是对
ResponseHandlerInterface怎么将这些网络请求结果告诉UI线程的呢？？？
那么接下来，我们去分析下AsyncHttpResponseHandler类吧，
至于怎么就跳到这个类了呢？接下来看下面一点。
*/</span>
responseHandler.sendResponseMessage(response);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (isCancelled()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Carry out post-processing for this response.</span>
responseHandler.onPostProcessResponse(responseHandler, response);
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li><li style="box-sizing: border-box; padding: 0px 5px;">69</li><li style="box-sizing: border-box; padding: 0px 5px;">70</li><li style="box-sizing: border-box; padding: 0px 5px;">71</li><li style="box-sizing: border-box; padding: 0px 5px;">72</li><li style="box-sizing: border-box; padding: 0px 5px;">73</li><li style="box-sizing: border-box; padding: 0px 5px;">74</li><li style="box-sizing: border-box; padding: 0px 5px;">75</li><li style="box-sizing: border-box; padding: 0px 5px;">76</li><li style="box-sizing: border-box; padding: 0px 5px;">77</li><li style="box-sizing: border-box; padding: 0px 5px;">78</li><li style="box-sizing: border-box; padding: 0px 5px;">79</li><li style="box-sizing: border-box; padding: 0px 5px;">80</li><li style="box-sizing: border-box; padding: 0px 5px;">81</li><li style="box-sizing: border-box; padding: 0px 5px;">82</li><li style="box-sizing: border-box; padding: 0px 5px;">83</li><li style="box-sizing: border-box; padding: 0px 5px;">84</li><li style="box-sizing: border-box; padding: 0px 5px;">85</li><li style="box-sizing: border-box; padding: 0px 5px;">86</li><li style="box-sizing: border-box; padding: 0px 5px;">87</li><li style="box-sizing: border-box; padding: 0px 5px;">88</li><li style="box-sizing: border-box; padding: 0px 5px;">89</li><li style="box-sizing: border-box; padding: 0px 5px;">90</li><li style="box-sizing: border-box; padding: 0px 5px;">91</li><li style="box-sizing: border-box; padding: 0px 5px;">92</li><li style="box-sizing: border-box; padding: 0px 5px;">93</li><li style="box-sizing: border-box; padding: 0px 5px;">94</li><li style="box-sizing: border-box; padding: 0px 5px;">95</li><li style="box-sizing: border-box; padding: 0px 5px;">96</li><li style="box-sizing: border-box; padding: 0px 5px;">97</li><li style="box-sizing: border-box; padding: 0px 5px;">98</li><li style="box-sizing: border-box; padding: 0px 5px;">99</li><li style="box-sizing: border-box; padding: 0px 5px;">100</li><li style="box-sizing: border-box; padding: 0px 5px;">101</li><li style="box-sizing: border-box; padding: 0px 5px;">102</li><li style="box-sizing: border-box; padding: 0px 5px;">103</li><li style="box-sizing: border-box; padding: 0px 5px;">104</li><li style="box-sizing: border-box; padding: 0px 5px;">105</li><li style="box-sizing: border-box; padding: 0px 5px;">106</li><li style="box-sizing: border-box; padding: 0px 5px;">107</li><li style="box-sizing: border-box; padding: 0px 5px;">108</li><li style="box-sizing: border-box; padding: 0px 5px;">109</li><li style="box-sizing: border-box; padding: 0px 5px;">110</li><li style="box-sizing: border-box; padding: 0px 5px;">111</li><li style="box-sizing: border-box; padding: 0px 5px;">112</li><li style="box-sizing: border-box; padding: 0px 5px;">113</li><li style="box-sizing: border-box; padding: 0px 5px;">114</li><li style="box-sizing: border-box; padding: 0px 5px;">115</li><li style="box-sizing: border-box; padding: 0px 5px;">116</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li><li style="box-sizing: border-box; padding: 0px 5px;">69</li><li style="box-sizing: border-box; padding: 0px 5px;">70</li><li style="box-sizing: border-box; padding: 0px 5px;">71</li><li style="box-sizing: border-box; padding: 0px 5px;">72</li><li style="box-sizing: border-box; padding: 0px 5px;">73</li><li style="box-sizing: border-box; padding: 0px 5px;">74</li><li style="box-sizing: border-box; padding: 0px 5px;">75</li><li style="box-sizing: border-box; padding: 0px 5px;">76</li><li style="box-sizing: border-box; padding: 0px 5px;">77</li><li style="box-sizing: border-box; padding: 0px 5px;">78</li><li style="box-sizing: border-box; padding: 0px 5px;">79</li><li style="box-sizing: border-box; padding: 0px 5px;">80</li><li style="box-sizing: border-box; padding: 0px 5px;">81</li><li style="box-sizing: border-box; padding: 0px 5px;">82</li><li style="box-sizing: border-box; padding: 0px 5px;">83</li><li style="box-sizing: border-box; padding: 0px 5px;">84</li><li style="box-sizing: border-box; padding: 0px 5px;">85</li><li style="box-sizing: border-box; padding: 0px 5px;">86</li><li style="box-sizing: border-box; padding: 0px 5px;">87</li><li style="box-sizing: border-box; padding: 0px 5px;">88</li><li style="box-sizing: border-box; padding: 0px 5px;">89</li><li style="box-sizing: border-box; padding: 0px 5px;">90</li><li style="box-sizing: border-box; padding: 0px 5px;">91</li><li style="box-sizing: border-box; padding: 0px 5px;">92</li><li style="box-sizing: border-box; padding: 0px 5px;">93</li><li style="box-sizing: border-box; padding: 0px 5px;">94</li><li style="box-sizing: border-box; padding: 0px 5px;">95</li><li style="box-sizing: border-box; padding: 0px 5px;">96</li><li style="box-sizing: border-box; padding: 0px 5px;">97</li><li style="box-sizing: border-box; padding: 0px 5px;">98</li><li style="box-sizing: border-box; padding: 0px 5px;">99</li><li style="box-sizing: border-box; padding: 0px 5px;">100</li><li style="box-sizing: border-box; padding: 0px 5px;">101</li><li style="box-sizing: border-box; padding: 0px 5px;">102</li><li style="box-sizing: border-box; padding: 0px 5px;">103</li><li style="box-sizing: border-box; padding: 0px 5px;">104</li><li style="box-sizing: border-box; padding: 0px 5px;">105</li><li style="box-sizing: border-box; padding: 0px 5px;">106</li><li style="box-sizing: border-box; padding: 0px 5px;">107</li><li style="box-sizing: border-box; padding: 0px 5px;">108</li><li style="box-sizing: border-box; padding: 0px 5px;">109</li><li style="box-sizing: border-box; padding: 0px 5px;">110</li><li style="box-sizing: border-box; padding: 0px 5px;">111</li><li style="box-sizing: border-box; padding: 0px 5px;">112</li><li style="box-sizing: border-box; padding: 0px 5px;">113</li><li style="box-sizing: border-box; padding: 0px 5px;">114</li><li style="box-sizing: border-box; padding: 0px 5px;">115</li><li style="box-sizing: border-box; padding: 0px 5px;">116</li></ul>4.AsyncHttpResponseHandler类
继承自ResponseHandlerInterface类，用来接收网络请求的结果，一般重写onSuccess及onFailure接收请求成功或失败的消息，还有onStart，onFinish等消息。
我们使用该框架的时候有一个参数，那就是AsyncHttpResponseHandler了，比如：
<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">AsyncHttpClient client = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> AsyncHttpClient();
client.get(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"http://www.google.com"</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> AsyncHttpResponseHandler() {
..............
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onSuccess</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> statusCode, Header[] headers, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">byte</span>[] response) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// called when response HTTP status is "200 OK"</span>
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onFailure</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> statusCode, Header[] headers, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">byte</span>[] errorResponse, Throwable e) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// called when response HTTP status is "4XX" (eg. 401, 403, 404)</span>
}
..............
});</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li></ul>就实现了AsyncHttpResponseHandler类的抽象方法。那么我们来看看这个类是怎么实现的？
在这里类里面，我们找到了这么一段代码
<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Avoid leaks by using a non-anonymous handler class.
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">ResponderHandler</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">extends</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">Handler</span> {</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> AsyncHttpResponseHandler mResponder;
ResponderHandler(AsyncHttpResponseHandler mResponder, Looper looper) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(looper);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>.mResponder = mResponder;
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">handleMessage</span>(Message msg) {
mResponder.handleMessage(msg);
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li></ul>这是一个内部Handler类，实现了Handler+Message消息处理机制用来进行子线程和UI线程通信。
既然是Handler消息处理机制，那么我们看看在这个类中哪里使用了该内部类发送消息？？跟踪代码如下：
<code class="hljs lasso has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">..</span>
@Override
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">void</span> setUseSynchronousMode(boolean sync) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// A looper must be prepared before setting asynchronous mode.</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (<span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">!</span>sync <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">&&</span> looper <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">==</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">null</span>) {
sync <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">=</span> <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">true</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Log</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>w(LOG_TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Current thread has not called Looper.prepare(). Forcing synchronous mode."</span>);
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// If using asynchronous mode.</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (<span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">!</span>sync <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">&&</span> handler <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">==</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">null</span>) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Create a handler on current thread to submit tasks</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//创建当前UI线程的Handler，用来发送异步任务结果给UI线程</span>
handler <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">=</span> <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">new</span> ResponderHandler(this, looper);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (sync <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">&&</span> handler <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">!=</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">null</span>) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// TODO: Consider adding a flag to remove all queued messages.</span>
handler <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">=</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">null</span>;
}
useSynchronousMode <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">=</span> sync;
}
<span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span><span class="hljs-attribute" style="box-sizing: border-box;">...</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">void</span> sendMessage(Message msg) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (getUseSynchronousMode() <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">||</span> handler <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">==</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">null</span>) {
handleMessage(msg);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (<span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">!</span><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Thread</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>currentThread()<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>isInterrupted()) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/*
do not send messages if request has been cancelled
*/</span>
Utils<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>asserts(handler <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">!=</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">null</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"handler should not be null!"</span>);
handler<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>sendMessage(msg);
}
}
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li></ul>在这个方法sendMessage()方法中调用了Handler的handler.sendMessage()方法。将异步任务结果发送给了UI线程。那到底哪里调用了这个方法呢？ 继续看代码发现：AsyncHttpResponseHandler类实现的接口方法
<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">sendSuccessMessage</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> statusCode, Header[] headers, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">byte</span>[] responseBytes) {
sendMessage(obtainMessage(SUCCESS_MESSAGE, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Object[]{statusCode, headers, responseBytes}));
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>这个接口是在AsyncHttpRequest子线程中被回调的，因此这里的
<code class="hljs javascript has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">sendMessage(obtainMessage(SUCCESS_MESSAGE, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">Object</span>[]{statusCode, headers, responseBytes}));</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>是在子线程中执行的，将回调的结果通过handler发送到UI线程中。
最后，所有的消息处理都跳转到这个方法：
<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Methods which emulate android's Handler and Message methods</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">handleMessage</span>(Message message) {
Object[] response;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">switch</span> (message.what) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">case</span> SUCCESS_MESSAGE:
response = (Object[]) message.obj;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (response != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> && response.length >= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>) {
onSuccess((Integer) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>], (Header[]) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>], (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">byte</span>[]) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>]);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
Log.e(LOG_TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"SUCCESS_MESSAGE didn't got enough params"</span>);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">case</span> FAILURE_MESSAGE:
response = (Object[]) message.obj;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (response != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> && response.length >= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>) {
onFailure((Integer) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>], (Header[]) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>], (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">byte</span>[]) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>], (Throwable) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>]);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
Log.e(LOG_TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"FAILURE_MESSAGE didn't got enough params"</span>);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">case</span> START_MESSAGE:
onStart();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">case</span> FINISH_MESSAGE:
onFinish();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">case</span> PROGRESS_MESSAGE:
response = (Object[]) message.obj;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (response != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> && response.length >= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
onProgress((Integer) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>], (Integer) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (Throwable t) {
Log.e(LOG_TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"custom onProgress contains an error"</span>, t);
}
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
Log.e(LOG_TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"PROGRESS_MESSAGE didn't got enough params"</span>);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">case</span> RETRY_MESSAGE:
response = (Object[]) message.obj;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (response != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> && response.length == <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>) {
onRetry((Integer) response[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>]);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
Log.e(LOG_TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"RETRY_MESSAGE didn't get enough params"</span>);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">case</span> CANCEL_MESSAGE:
onCancel();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">break</span>;
}
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span>(Throwable error) {
onUserException(error);
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li></ul>这里面调用了抽象方法 onSuccess和onFailure方法，让客户端去实现。至此，客户端通过实现
onSuccess和onFailure方法抽象方法来获得网络请求的结果。
源码分析大致如此。
开源框架总结：
几个关键的类： 1.AsyncHttpRequest： 继承自Runnabler，被线程池submit执行，用于真正执行网络异步请求的子线程。 2.ResponseHandlerInterface： 网络请求接口回调，用于将网络请求结果通过接口的方式回调给UI线程。 3.AsyncHttpResponseHandler： 继承自ResponseHandlerInterface，内部实现了一个消息处理机制，用于将接口回调的网络请求结果告诉UI线程。 4.AsyncHttpClient：
客户端网络请求核心类，使用HttpClient执行网络请求，提供了get，put，post，delete，head等请求方法，使用起来很简单，只需以url及RequestParams调用相应的方法即可，还可以选择性地传入Context，用于取消Content相关的请求，同时必须提供ResponseHandlerInterface（AsyncHttpResponseHandler继承自ResponseHandlerInterface）的实现类，一般为AsyncHttpResponseHandler的子类，AsyncHttpClient内部有一个线程池，当使用AsyncHttpClient执行网络请求时，最终都会调用sendRequest方法，在这个方法内部将请求参数封装成AsyncHttpRequest（继承自Runnable）交由内部的线程池执行。
框架请求流程
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