httpclient实例

在Android开发中，Android SDK附带了Apache的HttpClient，它是一个完善的客户端。它提供了对HTTP协议的全面支持，可以使用HttpClient的对象来执行HTTP GET和HTTP POST调用。 HTTP工作原理： 
1.客户端(一般是指浏览器，这里是指自己写的程序)与服务器建立连接 2.建立连接后，客户端向服务器发送请求 3.服务器接收到请求后，向客户端发送响应信息 4.客户端与服务器断开连接 HttpClient的一般使用步骤： 
1.使用DefaultHttpClient类实例化HttpClient对象 
2.创建HttpGet或HttpPost对象，将要请求的URL通过构造方法传入HttpGet或HttpPost对象。 
3.调用execute方法发送HTTP GET或HTTP POST请求，并返回HttpResponse对象。 4.通过HttpResponse接口的getEntity方法返回响应信息，并进行相应的处理。 最后记得要在AndroidManifest.xml文件添加网络权限 
<uses-permission android:name="android.permission.INTERNET" /> 

这里有一个非常棒的http通讯的总结，我看了以后茅塞顿开。

先贴代码：

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public class Activity1 extends Activity {
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    private final String DEBUG_TAG = "System.out";
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    private TextView mTextView;
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    private Button mButton;
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    protected void onCreate(Bundle savedInstanceState) {
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        super.onCreate(savedInstanceState);
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        setContentView(R.layout.main);
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        mTextView = (TextView) findViewById(R.id.TextView01);
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        mButton = (Button) findViewById(R.id.Button01);
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        mButton.setOnClickListener(new httpListener());
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    }
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    // 设置按钮监听器
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    class httpListener implements OnClickListener {
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        public void onClick(View v) {
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            refresh();
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        }
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    }
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    private void refresh() {
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        String httpUrl = "http://192.168.0.101:8080/Test/test.jsp";
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        // URL可以加参数
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        // String httpUrl =
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        // "http://192.168.0.101:8080/Test/test.jsp?par=abcdefg";
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        String resultData = "";
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        URL url = null;
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        try {
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            // 创建一个URL对象
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            url = new URL(httpUrl);
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        } catch (MalformedURLException e) {
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            Log.d(DEBUG_TAG, "create URL Exception");
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        }
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        // 声明HttpURLConnection对象
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        HttpURLConnection urlConn = null;
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        // 声明InputStreamReader对象
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        InputStreamReader in = null;
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        // 声明BufferedReader对象
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        BufferedReader buffer = null;
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        String inputLine = null;
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        if (url != null) {
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            try {
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                // 使用HttpURLConnection打开连接
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                urlConn = (HttpURLConnection) url.openConnection();
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                // 得到读取的内容(流)
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                in = new InputStreamReader(urlConn.getInputStream());
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                // 创建BufferReader对象，输出时候用到
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                buffer = new BufferedReader(in);
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                // 使用循环来读取数据
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                while ((inputLine = buffer.readLine()) != null) {
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                    // 在每一行后面加上换行
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                    resultData += inputLine + "
";
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                }
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                // 设置显示取的的内容
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                if (resultData != null && !resultData.equals("")) {
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                    mTextView.setText(resultData);
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                } else {
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                    mTextView.setText("读取的内容为空");
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                }
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            } catch (IOException e) {
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                e.printStackTrace();
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            } finally {
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                try {
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                    // 关闭InputStreamReader
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                    in.close();
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                    // 关闭URL连接
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                    urlConn.disconnect();
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                } catch (IOException e) {
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                    e.printStackTrace();
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                }
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            }
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        } else {
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            Log.d(DEBUG_TAG, "URL is NULL");
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        }
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    }
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}
 


第二种方式：

001
public class Activity2 extends Activity {
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    private final String DEBUG_TAG = "System.out";
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    private TextView mTextView;
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    private Button mButton;
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    protected void onCreate(Bundle savedInstanceState) {
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        super.onCreate(savedInstanceState);
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        setContentView(R.layout.main);
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        mTextView = (TextView) findViewById(R.id.TextView01);
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        mButton = (Button) findViewById(R.id.Button01);
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        mButton.setOnClickListener(new httpListener());
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    }
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    // 设置按钮监听器
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    class httpListener implements OnClickListener {
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        public void onClick(View v) {
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            refresh();
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        }
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    }
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    private void refresh() {
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        String httpUrl = "http://192.168.0.101:8080/Test/test.jsp";
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        String resultData = "";
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        URL url = null;
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        try {
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            // 创建一个URL对象
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            url = new URL(httpUrl);
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        } catch (MalformedURLException e) {
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            Log.d(DEBUG_TAG, "create URL Exception");
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        }
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        // 声明HttpURLConnection对象
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        HttpURLConnection urlConn = null;
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        // 声明InputStreamReader对象
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        InputStreamReader in = null;
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        // 声明BufferedReader对象
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        BufferedReader buffer = null;
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        String inputLine = null;
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        // 声明DataOutputStream流
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        DataOutputStream out = null;
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        if (url != null) {
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            try {
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                // 使用HttpURLConnection打开连接
046
                urlConn = (HttpURLConnection) url.openConnection();
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                // 因为这个是POST请求所以要设置为true
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                urlConn.setDoInput(true);
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                urlConn.setDoOutput(true);
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                // 设置POST方式
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                urlConn.setRequestMethod("POST");
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                // POST请求不能设置缓存
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                urlConn.setUseCaches(false);
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                urlConn.setInstanceFollowRedirects(false);
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                // 配置本次连接的Content-type，配置为application/x-www-form-urlencoded的
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                urlConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
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                // 连接，从postUrl.openConnection()至此的配置必须要在connect之前完成
058
                // 要注意的是connectio.getOutputStream会隐含的进行connect
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                urlConn.connect();
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                // DataOutputStream流
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                out = new DataOutputStream(urlConn.getOutputStream());
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                String content = "par=" + URLEncoder.encode("abcdefg", "gb2312");
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                // 将要上传的内容写入流中
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                out.writeBytes(content);
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                // 得到读取的内容(流)
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                in = new InputStreamReader(urlConn.getInputStream());
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                // 创建BufferReader对象，输出时候用到
068
                buffer = new BufferedReader(in);
069
                // 使用循环来读取数据
070
                while ((inputLine = buffer.readLine()) != null) {
071
                    // 在每一行后面加上换行
072
                    resultData += inputLine + "
";
073
                }
074
                // 设置显示取的的内容
075
                if (resultData != null && !resultData.equals("")) {
076
                    mTextView.setText(resultData);
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                } else {
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                    mTextView.setText("读取的内容为空");
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                }
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            } catch (IOException e) {
081
                e.printStackTrace();
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            } finally {
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                try {
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                    // 刷新DataOutputStream流
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                    out.flush();
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                    // 关闭DataOutputStream流
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                    out.close();
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                    // 关闭InputStreamReader
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                    in.close();
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                    // 关闭URL连接
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                    urlConn.disconnect();
092
                } catch (IOException e) {
093
                    e.printStackTrace();
094
                }
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            }
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        } else {
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            Log.d(DEBUG_TAG, "URL is NULL");
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        }
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    }
100
}
 

第三种方式

01
public class Activity3 extends Activity{
02
    private TextView mTextView;
03
    private Button mButton;
04
 
05
    protected void onCreate(Bundle savedInstanceState) {
06
        super.onCreate(savedInstanceState);
07
        setContentView(R.layout.main);
08
        mTextView = (TextView) findViewById(R.id.TextView01);
09
        mButton = (Button) findViewById(R.id.Button01);
10
        mButton.setOnClickListener(new httpListener());
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    }
12
 
13
    // 设置按钮监听器
14
    class httpListener implements OnClickListener {
15
        public void onClick(View v) {
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            String httpUrl = "http://192.168.0.101:8080/Test/test.jsp?par=HttpClient_android_Get";
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            // HttpGet连接对象
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            HttpGet httpRequest = new HttpGet(httpUrl);
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            try {
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                // 取的HttpClient对象
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                HttpClient httpclient = new DefaultHttpClient();
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                // 请求HttpClient，取的HttpResponse
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                HttpResponse httpResponse = httpclient.execute(httpRequest);
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                // 请求成功
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                if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
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                    // 取的返回的字符串
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                    String strResult = EntityUtils.toString(httpResponse.getEntity());
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                    // 这个返回值可能会在行尾出现小方格
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                    // 在TextView要显示的文字过滤掉回车符（"
"）就可以正常显示了。
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                    String strsResult = strResult.replace("
", "");
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                    mTextView.setText(strsResult);
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                } else {
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                    mTextView.setText("请求错误");
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                }
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            } catch (ClientProtocolException e) {
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                mTextView.setText(e.getMessage().toString());
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            } catch (IOException e) {
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                mTextView.setText(e.getMessage().toString());
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            } catch (Exception e) {
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                mTextView.setText(e.getMessage().toString());
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            }
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        }
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    }
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}
 

第四种方式

01
public class Activity4 extends Activity{
02
    private TextView mTextView;
03
    private Button mButton;
04
 
05
    protected void onCreate(Bundle savedInstanceState) {
06
        super.onCreate(savedInstanceState);
07
        setContentView(R.layout.main);
08
        mTextView = (TextView) findViewById(R.id.TextView01);
09
        mButton = (Button) findViewById(R.id.Button01);
10
        mButton.setOnClickListener(new httpListener());
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    }
12
 
13
    // 设置按钮监听器
14
    class httpListener implements OnClickListener {
15
        public void onClick(View arg0) {
16
            String httpUrl = "http://192.168.0.101:8080/Test/test.jsp";
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            // 创建HttpPost连接对象
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            HttpPost httpRequest = new HttpPost(httpUrl);
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            // 使用NameValuePair来保存要传递的Post参数
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            List params = new ArrayList();
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            // 添加要传递的参数
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            params.add(new BasicNameValuePair("par","HttpClient_android_Post"));
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            try {
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                // 设置字符集
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                HttpEntity httpentity = new UrlEncodedFormEntity(params,"gb2312");
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                // 请求httpRequest
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                httpRequest.setEntity(httpentity);
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                // 取的默认的HttpClient
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                HttpClient httpclient = new DefaultHttpClient();
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                // 取的HttpResponse
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                HttpResponse httpResponse = httpclient.execute(httpRequest);
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                // HttpStatus.SC_OK表示连接成功
33
                if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
34
                    // 取的返回的字符串
35
                    String strResult = EntityUtils.toString(httpResponse.getEntity());
36
                    // 这个返回值可能会在行尾出现小方格
37
                    // 在TextView要显示的文字过滤掉回车符（"
"）就可以正常显示了。
38
                    String strsResult = strResult.replace("
", "");
39
                    mTextView.setText(strsResult);
40
                } else {
41
                    mTextView.setText("请求错误");
42
                }
43
            } catch (ClientProtocolException e) {
44
                mTextView.setText(e.getMessage().toString());
45
            } catch (IOException e) {
46
                mTextView.setText(e.getMessage().toString());
47
            } catch (Exception e) {
48
                mTextView.setText(e.getMessage().toString());
49
            }
50
        }
51
    }
52
}

文章出处：1、http://blog.csdn.net/jdsjlzx/article/details/6876958 2、http://wenku.baidu.com/link?url=1IuuCu1wvwVjpcRZQ8WN0--lDTzazCXM0CMTpZ84ROI9acdPpQiQ-yXL9JqpSjsDegGHDGbiVgkfZOR5KhNuFEeH4ZuWGha1ch9CVrCJjkW