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>