极光推送Java SDK源码学习

前一段时间使用JPush搞了一下推送，服务器用的SpringMVC，所以想看看他的SDK源码。结果呢，一般般，没有很惊艳的感觉，看别人的代码总想去批评，这不好，但是有点失望吧~~

JPush核心有两个部分，一个是JPushClient，一个是Payload

JPushClient

内部有四个属性PushClient，ReportClient，DeviceClient，ScheduleClient。

这四个Client都是使用NativeHttpClient实现发送的，NativeHttpClient实现了IHttpClient接口

public interface IHttpClient {

public static final String CHARSET = "UTF-8";
public static final String CONTENT_TYPE_JSON = "application/json";
public static final String CONTENT_TYPE_FORM = "application/x-www-form-urlencoded";

public static final String RATE_LIMIT_QUOTA = "X-Rate-Limit-Limit";
public static final String RATE_LIMIT_Remaining = "X-Rate-Limit-Remaining";
public static final String RATE_LIMIT_Reset = "X-Rate-Limit-Reset";
public static final String JPUSH_USER_AGENT = "JPush-API-Java-Client";

public static final int RESPONSE_OK = 200;

public enum RequestMethod {
GET,
POST,
PUT,
DELETE
}

public static final String IO_ERROR_MESSAGE = "Connection IO error. \n"
+ "Can not connect to JPush Server. "
+ "Please ensure your internet connection is ok. \n"
+ "If the problem persists, please let us know at support@jpush.cn.";

public static final String CONNECT_TIMED_OUT_MESSAGE = "connect timed out. \n"
+ "Connect to JPush Server timed out, and already retried some times. \n"
+ "Please ensure your internet connection is ok. \n"
+ "If the problem persists, please let us know at support@jpush.cn.";

public static final String READ_TIMED_OUT_MESSAGE = "Read timed out. \n"
+ "Read response from JPush Server timed out. \n"
+ "If this is a Push action, you may not want to retry. \n"
+ "It may be due to slowly response from JPush server, or unstable connection. \n"
+ "If the problem persists, please let us know at support@jpush.cn.";

public static Gson _gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation().create();

//设置连接超时时间
public static final int DEFAULT_CONNECTION_TIMEOUT = (5 * 1000); // milliseconds

//设置读取超时时间
public static final int DEFAULT_READ_TIMEOUT = (30 * 1000); // milliseconds

public static final int DEFAULT_MAX_RETRY_TIMES = 3;

public ResponseWrapper sendGet(String url)
throws APIConnectionException, APIRequestException;

public ResponseWrapper sendDelete(String url)
throws APIConnectionException, APIRequestException;

public ResponseWrapper sendPost(String url, String content)
throws APIConnectionException, APIRequestException;

public ResponseWrapper sendPut(String url, String content)
throws APIConnectionException, APIRequestException;
}

而NativeHttpClient的核心代码使用了HttpURLConnection，没有连接池，JPush的服务器使用了Yii做流量控制，这些我们都没办法改变

private ResponseWrapper _doRequest(String url, String content,
RequestMethod method) throws APIConnectionException, APIRequestException,
SocketTimeoutException {

LOG.debug("Send request - " + method.toString() + " "+ url);
if (null != content) {
LOG.debug("Request Content - " + content);
}
HttpURLConnection conn = null;
OutputStream out = null;
StringBuffer sb = new StringBuffer();
ResponseWrapper wrapper = new ResponseWrapper();

try {
URL aUrl = new URL(url);

if (null != _proxy) {
conn = (HttpURLConnection) aUrl.openConnection(_proxy.getNetProxy());
if (_proxy.isAuthenticationNeeded()) {
conn.setRequestProperty("Proxy-Authorization", _proxy.getProxyAuthorization());
}
} else {
conn = (HttpURLConnection) aUrl.openConnection();
}

conn.setConnectTimeout(_connectionTimeout);
conn.setReadTimeout(_readTimeout);
conn.setUseCaches(false);
conn.setRequestMethod(method.name());
conn.setRequestProperty("User-Agent", JPUSH_USER_AGENT);
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Accept-Charset", CHARSET);
conn.setRequestProperty("Charset", CHARSET);
conn.setRequestProperty("Authorization", _authCode);
conn.setRequestProperty("Content-Type", CONTENT_TYPE_JSON);

if(null == content) {
conn.setDoOutput(false);
} else {
conn.setDoOutput(true);
byte[] data = content.getBytes(CHARSET);
conn.setRequestProperty("Content-Length", String.valueOf(data.length));
out = conn.getOutputStream();
out.write(data);
out.flush();
}

int status = conn.getResponseCode();
InputStream in = null;
if (status / 100 == 2) {
in = conn.getInputStream();
} else {
in = conn.getErrorStream();
}

if (null != in) {
InputStreamReader reader = new InputStreamReader(in, CHARSET);
char[] buff = new char[1024];
int len;
while ((len = reader.read(buff)) > 0) {
sb.append(buff, 0, len);
}
}

String responseContent = sb.toString();
wrapper.responseCode = status;
wrapper.responseContent = responseContent;

String quota = conn.getHeaderField(RATE_LIMIT_QUOTA);
String remaining = conn.getHeaderField(RATE_LIMIT_Remaining);
String reset = conn.getHeaderField(RATE_LIMIT_Reset);
wrapper.setRateLimit(quota, remaining, reset);

if (status >= 200 && status < 300) {
LOG.debug("Succeed to get response OK - responseCode:" + status);
LOG.debug("Response Content - " + responseContent);

} else if (status >= 300 && status < 400) {
LOG.warn("Normal response but unexpected - responseCode:" + status + ", responseContent:" + responseContent);

} else {
LOG.warn("Got error response - responseCode:" + status + ", responseContent:" + responseContent);

switch (status) {
case 400:
LOG.error("Your request params is invalid. Please check them according to error message.");
wrapper.setErrorObject();
break;
case 401:
LOG.error("Authentication failed! Please check authentication params according to docs.");
wrapper.setErrorObject();
break;
case 403:
LOG.error("Request is forbidden! Maybe your appkey is listed in blacklist or your params is invalid.");
wrapper.setErrorObject();
break;
case 404:
LOG.error("Request page is not found! Maybe your params is invalid.");
wrapper.setErrorObject();
break;
case 410:
LOG.error("Request resource is no longer in service. Please according to notice on official website.");
wrapper.setErrorObject();
case 429:
LOG.error("Too many requests! Please review your appkey's request quota.");
wrapper.setErrorObject();
break;
case 500:
case 502:
case 503:
case 504:
LOG.error("Seems encountered server error. Maybe JPush is in maintenance? Please retry later.");
break;
default:
LOG.error("Unexpected response.");
}

throw new APIRequestException(wrapper);
}

} catch (SocketTimeoutException e) {
if (e.getMessage().contains(KEYWORDS_CONNECT_TIMED_OUT)) {
throw e;
} else if (e.getMessage().contains(KEYWORDS_READ_TIMED_OUT)) {
throw new SocketTimeoutException(KEYWORDS_READ_TIMED_OUT);
}
LOG.debug(IO_ERROR_MESSAGE, e);
throw new APIConnectionException(IO_ERROR_MESSAGE, e);

} catch (IOException e) {
LOG.debug(IO_ERROR_MESSAGE, e);
throw new APIConnectionException(IO_ERROR_MESSAGE, e);

} finally {
if (null != out) {
try {
out.close();
} catch (IOException e) {
LOG.error("Failed to close stream.", e);
}
}
if (null != conn) {
conn.disconnect();
}
}

return wrapper;
}

PushPayload

private final Platform platform;
private final Audience audience;
private final Notification notification;
private final Message message;
private Options options;
private SMS sms;

PushPayload是推送的内容，使用builder模式，分为以下几个属性：

Platform表示推送平台，ios，Android，wp

Audience表示接受者，可以有别名，标签等方式

Notification表示接受推送的一些定制，比如声音之类的（这里面还需要根据不同的平台设置，感觉和Platform有些重复）

Message表示消息具体内容

Options表示额外选项

SMS表示短信

也许是建议

没有连接池

设计了过多的model，但是却没有一个舒服的继承关系

很多都是这样，而且重复

public interface PushModel {

public static Gson gson = new Gson();
public JsonElement toJSON();

}

public interface IModel {

public JsonElement toJSON();
}

Result的Model为什么不能统一下一，搞了好多。。这样不行吗

public class ResultCode<T> implements Serializable {
private String errMsg;
private int errCode;
private T data;
}

命名太尴尬，”_”符号我明白是内部实现的意思，但这是java啊！private不就够了，这种C的命名看起来累人！

private final NativeHttpClient _httpClient;
private String _baseUrl;
private String _pushPath;
private String _pushValidatePath;

如果你是JPush Java SDK的开发人员，别打我- -b

任何逃开实际开发环境的讨论代码都是耍流氓，这个我懂，但是我还是失望了