Http与HttpClient（已被废弃）通信的介绍，附带一个Http发送GET请求工具类的例子

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所谓通信便有发送和接受两种形式，在代码的表现则是POST和GET

以下的URL是笔者随写的，读者根据实际开发进行修改，仅供参考！

             *Http的GET请求，得到数据*

第一种方式，开启线程请求数据

package com.example.getposthttp;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import org.apache.http.client.methods.HttpUriRequest;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.ContactsContract.Contacts.Data;
import android.view.View;
import android.view.View.OnClickListener;

public class GetDemo extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.btn_read).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                sendRequestWithHttpURLConnection();
            }
        });
    }

    private void sendRequestWithHttpURLConnection() {
        // 开启线程来发起网络请求
        new Thread(new Runnable() {

            @Override
            public void run() {
                /**
 * HttpURLConnection代表应用程序和 URL 之间的通信链接。 此类的实例可用于读取和写入此 URL
 * 引用的资源
 */
                HttpURLConnection cOnnection= null;
                try {
                    URL url = new URL("http://www.baidu.com");
                    // 表示到 URL 所引用的远程对象的连接
                    cOnnection= (HttpURLConnection) url.openConnection();
                    // GET从服务器获取数据
                    connection.setRequestMethod("GET");
                    // 设置一个指定的超时值（以毫秒为单位），该值将在打开到此 URLConnection
                    // 引用的资源的通信链接时使用。
                    connection.setConnectTimeout(8000);
                    // 返回读入超时设置
                    connection.setReadTimeout(8000);
                    // 得到输入流对象
                    InputStream in = connection.getInputStream();
                    // 下面对获取到的输入流进行读取
                    BufferedReader reader = new BufferedReader(
                            new InputStreamReader(in));
                    StringBuilder respOne= new StringBuilder();
                    String line;
                    while ((line = reader.readLine()) != null) {
                        respone.append(line);
                    }
                    System.out.println(respone.toString());
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }).start();
    }
}

第二种方式，使用异步请求数据

  package com.example.getposthttp;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import org.apache.http.client.methods.HttpUriRequest;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.ContactsContract.Contacts.Data;
import android.view.View;
import android.view.View.OnClickListener;

public class GetDemo extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.btn_read).setOnClickListener(
                new View.OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        // TODO Auto-generated method stub
                        new AsyncTask() {

                            @Override
                            protected Void doInBackground(String... params) {
                                try {
                                    URL url = new URL(params[0]);

                                    try {
                                        URLConnection cOnnection= url
                                                .openConnection();

                                        InputStream is = connection
                                                .getInputStream();

                                        InputStreamReader isr = new InputStreamReader(
                                                is, "uft-8");

                                        BufferedReader br = new BufferedReader(
                                                isr);

                                        String line;

                                        while ((line = br.readLine()) != null) {
                                            System.out.println(line);

                                        }
                                        br.close();
                                        isr.close();
                                        is.close();
                                    } catch (IOException e) {
                                        // TODO Auto-generated catch block
                                        e.printStackTrace();
                                    }
                                } catch (MalformedURLException e) {
                                    // TODO Auto-generated catch block
                                    e.printStackTrace();
                                }
                                return null;
                            }
                        }.execute("http://fanyi.youdao.com/openapi.do?keyfrom=YouDaoXY&key=659600044&type=data&doctype=json&version=1.1&q=good");
                    }
                });
    }
}

                   *Http的Post请求，发送数据*

第一种方式：开启线程

package com.example.getposthttp;

import java.io.DataOutputStream;
import java.net.URL;
import java.net.URLConnection;

import org.apache.http.client.methods.HttpUriRequest;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.ContactsContract.Contacts.Data;
import android.view.View;
import android.view.View.OnClickListener;

public class GetDemo extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.btn_read).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                sendRequestWithHttpURLConnection();
            }
        });
    }

    private void sendRequestWithHttpURLConnection()
    {
        //开启线程来发起网络请求
        new Thread(new Runnable() {

            @Override
            public void run() {
                /**
 * HttpURLConnection代表应用程序和 URL 之间的通信链接。
 * 此类的实例可用于读取和写入此 URL 引用的资源
 */
                HttpURLConnection cOnnection=null;
                try {
                    URL url=new URL("http://www.baidu.com");
                    //表示到 URL 所引用的远程对象的连接
                    cOnnection=(HttpURLConnection) url.openConnection();
                    //POST提交数据给服务器
                    connection.setRequestMethod("POST");
                    //得到输出流
                    DataOutputStream out=new DataOutputStream(connection.getOutputStream());
                    //发送数据
                    out.writeBytes("");
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }).start();
    }
}

第二种方式：使用异步

package com.example.getposthttp;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;

public class PostDemo extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.btn_read).setOnClickListener(
                new View.OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        // TODO Auto-generated method stub
                        new AsyncTask() {

                            @Override
                            protected Void doInBackground(String... params) {
                                try {
                                    URL url = new URL(params[0]);

                                    try {
                                        HttpURLConnection cOnnection= (HttpURLConnection) url
                                                .openConnection();
                                        connection.setRequestMethod("POST");
                                        // 将此 URLConnection 的 doInput 字段的值设置为指定的值
                                        connection.setDoInput(true);
                                        // 将此 URLConnection 的 doOutput 字段的值设置为指定的值。
                                        connection.setDoOutput(true);
                                        //得到输出流
                                        OutputStreamWriter osw=new OutputStreamWriter(connection.getOutputStream());

                                        BufferedWriter bw=new BufferedWriter(osw);

                                        bw.write("?keyfrom=YouDaoXY&key=659600044&type=data&doctype=json&version=1.1&q=good");

                                        bw.flush();

                                        InputStream is = connection
                                                .getInputStream();

                                        InputStreamReader isr = new InputStreamReader(
                                                is, "uft-8");

                                        BufferedReader br = new BufferedReader(
                                                isr);

                                        String line;

                                        while ((line = br.readLine()) != null) {
                                            System.out.println(line);

                                        }
                                        br.close();
                                        isr.close();
                                        is.close();
                                    } catch (IOException e) {
                                        // TODO Auto-generated catch block
                                        e.printStackTrace();
                                    }
                                } catch (MalformedURLException e) {
                                    // TODO Auto-generated catch block
                                    e.printStackTrace();
                                }
                                return null;
                            }
                        }.execute("http://fanyi.youdao.com/openapi.do");
                    }
                });
    }
}

                HttpClient的GET请求

public void sendRequestWithHttpClient()
    {
        new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    //获取HttpClient实例，HttpClient是一个接口
                    HttpClient httpClient=new DefaultHttpClient();
                    //HttpGet表示发送get请求
                    HttpGet httpGet=new HttpGet("http://www.baidu.com");
                    //发送Get请求
                    HttpResponse httpRespOnse=httpClient.execute(httpGet);
                    //如果状态码=200
                    if (httpResponse.getStatusLine().getStatusCode()==200) {
                        //请求和响应都成功了，得到请求实体数据
                        HttpResponse entity=(HttpResponse) httpResponse.getEntity();
                        //转换成String类型
                        String respOnes=EntityUtils.toString((HttpEntity) entity,"UTF-8");
                        text.setText(respones);
                    }
                } catch (Exception e) {
                    // TODO: handle exception
                }
            }
        });
    }

                  *HttpClient的Post请求*     

private void ReceiverResponeWithHttpClient()
    {
        new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    //获取HttpClient实例，HttpClient是一个接口
                    HttpClient httpClient=new DefaultHttpClient();
                    //HttpGPost表示发送Post请求
                    HttpPost httpPost=new HttpPost("http://www.baidu.com");
                    //NameValuePair将某一名称与一个属性为 IDL struct 的值关联，并在 DynStruct API 中使用。
                    //简单点的意思就是键值对的意思，前面是键，后面是值
                    List params=new ArrayList();
                    //以键值对的形式添加
                    params.add(new BasicNameValuePair("username", "adaim"));
                    params.add(new BasicNameValuePair("password", "123456"));
                    //UrlEncodedFormEntity这个类是用来把输入的数据编码成合适的数据
                    UrlEncodedFormEntity entity=new UrlEncodedFormEntity(params,"uft-8");
                    httpPost.setEntity(entity);
                    HttpResponse httpRespOnse=httpClient.execute(httpPost);


                } catch (Exception e) {
                    // TODO: handle exception
                }
            }
        });
    }

到这里Http与HttpClient已经介绍完了

由于一个项目可能很多地方会用到GET和POST请求，我们不可能每次都去重复写一次，所以我们一般会去写个工具类，下面是我写的一个Http发送GET请求工具类的例子，希望读者能够举一反三，下面用到了回调机制，回调机制的用法及其作用读者可以自行研究一下，这里就不介绍了。

首先定义一个回调接口

package com.example.getposthttp;

public interface HttpCallBackListener {

    void onFinish(String respones);
    void onError(Exception e);
}

package com.example.getposthttp;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;


/**
 * 回调机制
 * @author Administrator
 *
 */
public class HttpUtil {

    private static void sendRequestWithHttpURLConnection(final String address,
            final HttpCallBackListener listener) {
        // 开启线程来发起网络请求
        new Thread(new Runnable() {

            @Override
            public void run() {
                HttpURLConnection cOnnection= null;
                try {
                    URL url = new URL(address);
                    cOnnection= (HttpURLConnection) url.openConnection();

                    // GET从服务器获取数据
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    connection.setDoInput(true);
                    connection.setDoOutput(true);
                    InputStream in = connection.getInputStream();
                    // 下面对获取到的输入流进行读取
                    BufferedReader reader = new BufferedReader(
                            new InputStreamReader(in));
                    StringBuilder respOne= new StringBuilder();
                    String line;
                    while ((line = reader.readLine()) != null) {
                        respone.append(line);
                    }
                    if (listener!=null) {
                        //回调onFinish方法
                        listener.onFinish(respone.toString());
                    }
                } catch (Exception e) {
                    if (listener!=null) {
                        //回调onError方法
                        listener.onError(e);
                    }
                }finally{
                    if (connection!=null) {
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }
}

                *谢谢观看，欢迎转载*