Android Http请求方法汇总

这篇文章主要实现了在Android中使用JDK的HttpURLConnection和Apache的HttpClient访问网络资源，服务端采用python+flask编写，使用Servlet太麻烦了。关于Http协议的相关知识，可以在网上查看相关资料。代码比较简单，就不详细解释了。

1. 使用JDK中HttpURLConnection访问网络资源

(1)get请求

public String executeHttpGet() {
String result = null;
URL url = null;
HttpURLConnection connection = null;
InputStreamReader in = null;
try {
url = new URL("http://10.0.2.2:8888/data/get/?token=alexzhou");
connection = (HttpURLConnection) url.openConnection();
in = new InputStreamReader(connection.getInputStream());
BufferedReader bufferedReader = new BufferedReader(in);
StringBuffer strBuffer = new StringBuffer();
String line = null;
while ((line = bufferedReader.readLine()) != null) {
strBuffer.append(line);
}
result = strBuffer.toString();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}

}
return result;
}

注意：因为是通过android模拟器访问本地pc服务端，所以不能使用localhost和127.0.0.1，使用127.0.0.1会访问模拟器自身。Android系统为实现通信将PC的IP设置为10.0.2.2

(2)post请求

public String executeHttpPost() {
String result = null;
URL url = null;
HttpURLConnection connection = null;
InputStreamReader in = null;
try {
url = new URL("http://10.0.2.2:8888/data/post/");
connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestProperty("Charset", "utf-8");
DataOutputStream dop = new DataOutputStream(
connection.getOutputStream());
dop.writeBytes("token=alexzhou");
dop.flush();
dop.close();

in = new InputStreamReader(connection.getInputStream());
BufferedReader bufferedReader = new BufferedReader(in);
StringBuffer strBuffer = new StringBuffer();
String line = null;
while ((line = bufferedReader.readLine()) != null) {
strBuffer.append(line);
}
result = strBuffer.toString();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}

}
return result;
}

如果参数中有中文的话，可以使用下面的方式进行编码解码：

URLEncoder.encode("测试","utf-8")
URLDecoder.decode("测试","utf-8");

2.使用Apache的HttpClient访问网络资源

(1)get请求

public String executeGet() {
String result = null;
BufferedReader reader = null;
try {
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet();
request.setURI(new URI(
"http://10.0.2.2:8888/data/get/?token=alexzhou"));
HttpResponse response = client.execute(request);
reader = new BufferedReader(new InputStreamReader(response
.getEntity().getContent()));

StringBuffer strBuffer = new StringBuffer("");
String line = null;
while ((line = reader.readLine()) != null) {
strBuffer.append(line);
}
result = strBuffer.toString();

} catch (Exception e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
reader = null;
} catch (IOException e) {
e.printStackTrace();
}
}
}

return result;
}

（2）post请求

public String executePost() {
String result = null;
BufferedReader reader = null;
try {
HttpClient client = new DefaultHttpClient();
HttpPost request = new HttpPost();
request.setURI(new URI("http://10.0.2.2:8888/data/post/"));
List<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("token", "alexzhou"));
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(
postParameters);
request.setEntity(formEntity);

HttpResponse response = client.execute(request);
reader = new BufferedReader(new InputStreamReader(response
.getEntity().getContent()));

StringBuffer strBuffer = new StringBuffer("");
String line = null;
while ((line = reader.readLine()) != null) {
strBuffer.append(line);
}
result = strBuffer.toString();

} catch (Exception e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
reader = null;
} catch (IOException e) {
e.printStackTrace();
}
}
}

return result;
}

3.服务端代码实现

上面是采用两种方式的get和post请求的代码，下面来实现服务端的代码编写，使用python+flask真的非常的简单，就一个文件，前提是你得搭建好python+flask的环境，代码如下：

#coding=utf-8

import json
from flask import Flask,request,render_template

app = Flask(__name__)

def send_ok_json(data=None):
if not data:
data = {}
ok_json = {'ok':True,'reason':'','data':data}
return json.dumps(ok_json)

@app.route('/data/get/',methods=['GET'])
def data_get():
token = request.args.get('token')
ret = '%s**%s' %(token,'get')
return send_ok_json(ret)

@app.route('/data/post/',methods=['POST'])
def data_post():
token = request.form.get('token')
ret = '%s**%s' %(token,'post')
return send_ok_json(ret)

if __name__ == "__main__":
app.run(host="localhost",port=8888,debug=True)

运行服务器，如图：



4. 编写单元测试代码

右击项目：new–》Source Folder取名tests，包名是：com.alexzhou.androidhttp.test（随便取，没有要求），结构如图：



在该包下创建测试类HttpTest，继承自AndroidTestCase。编写这四种方式的测试方法，代码如下:

public class HttpTest extends AndroidTestCase {

@Override
protected void setUp() throws Exception {
Log.e("HttpTest", "setUp");
}

@Override
protected void tearDown() throws Exception {
Log.e("HttpTest", "tearDown");
}

public void testExecuteGet() {
Log.e("HttpTest", "testExecuteGet");
HttpClientTest client = HttpClientTest.getInstance();
String result = client.executeGet();
Log.e("HttpTest", result);
}

public void testExecutePost() {
Log.e("HttpTest", "testExecutePost");
HttpClientTest client = HttpClientTest.getInstance();
String result = client.executePost();
Log.e("HttpTest", result);
}

public void testExecuteHttpGet() {
Log.e("HttpTest", "testExecuteHttpGet");
HttpClientTest client = HttpClientTest.getInstance();
String result = client.executeHttpGet();
Log.e("HttpTest", result);
}

public void testExecuteHttpPost() {
Log.e("HttpTest", "testExecuteHttpPost");
HttpClientTest client = HttpClientTest.getInstance();
String result = client.executeHttpPost();
Log.e("HttpTest", result);
}
}

附上HttpClientTest.java的其他代码：

public class HttpClientTest {

private static final Object mSyncObject = new Object();
private static HttpClientTest mInstance;

private HttpClientTest() {

}

public static HttpClientTest getInstance() {
synchronized (mSyncObject) {
if (mInstance != null) {
return mInstance;
}
mInstance = new HttpClientTest();
}
return mInstance;
}

/**...上面的四个方法...*/
}

现在还需要修改Android项目的配置文件AndroidManifest.xml，添加网络访问权限和单元测试的配置，AndroidManifest.xml配置文件的全部代码如下：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.alexzhou.androidhttp"
android:versionCode="1"
android:versionName="1.0" >

<uses-permission android:name="android.permission.INTERNET" />

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="15" />

<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<uses-library android:name="android.test.runner" />

<activity
android:name=".MainActivity"
android:label="@string/title_activity_main" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

<instrumentation
android:name="android.test.InstrumentationTestRunner"
android:targetPackage="com.alexzhou.androidhttp" />

</manifest>

注意：

android:name=”android.test.InstrumentationTestRunner”这部分不用更改

android:targetPackage=”com.alexzhou.androidhttp”，填写应用程序的包名

5.测试结果

展开测试类HttpTest，依次选中这四个测试方法，右击：Run As–》Android Junit Test。

(1)运行testExecuteHttpGet，结果如图：


(2)运行testExecuteHttpPost，结果如图：


(3)运行testExecuteGet，结果如图：


(4)运行testExecutePost，结果如图：