android之HttpClient

Apache包是对android联网访问封装的很好的一个包，也是android访问网络最常用的类。

下面分别讲一下怎么用HttpClient实现get，post请求。

1.Get 请求

HttpGet get = new HttpGet("http://www.baidu.com");

HttpClient hClient = new DefaultHttpClient();

httpResponse = hClient.execute(get);

　　

2.Post 请求

Map<String, String> map = new HashMap<String, String>();
map.put("id", id);
map.put("name", name);
map.put("permission", String.valueOf(permission));

 List<NameValuePair> list = new ArrayList<NameValuePair>();
 if(map != null && !map.isEmpty()){
 for(Map.Entry<String, String> entry : map.entrySet()){//迭代器
 //键值对
 NameValuePair nameValuePair = new BasicNameValuePair(entry.getKey(), entry.getValue());
 list.add(nameValuePair);
 }
 }

UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list ,encode);
//使用post方式提交数据
HttpPost post = new HttpPost(path);
post.setEntity(entity);//请求体中
//默认客户端
HttpClient client = httpClient;

HttpResponse httpResponse = client.execute(post);

　　

3.代码实例：

先是get请求

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;  

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.DefaultHttpClientConnection;
import org.apache.http.impl.client.DefaultHttpClient;  

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;  

public class MainActivity extends Activity {  

    private Button requestButton;
    private HttpResponse httpResponse;
    private HttpEntity entity;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        requestButton = (Button) findViewById(R.id.requestButton);  

        requestButton.setOnClickListener(new OnClickListener() {  

            public void onClick(View v) {
                 new Thread(new Downtest()).start();
            }
        });
    }
   class Downtest implements Runnable{  

      public void run() {
        //生成一个请求对象,请求
            HttpGet get = new HttpGet("http://www.baidu.com");
            //生成一个Http客户端对象
            HttpClient hClient = new DefaultHttpClient();
            //使用Http客户端发送请求对象
            InputStream inputStream = null;
            try {
                httpResponse = hClient.execute(get);//httpResponse返回的响应
              //返回的响应数据就放在里边
                entity = httpResponse.getEntity();
                inputStream = entity.getContent();
                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
                String result = "";
                String line = "";
               while((line = reader.readLine())!= null){
                   result = result+ line;
               }
               System.out.println(result);
            } catch (ClientProtocolException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally{
                try{
                    inputStream.close();
                }catch(Exception e){
                    e.printStackTrace();
                }
            }
     }
   }   

}

　　再是post请求

public class AccountHttpUtils {  

    //private static String PATH = "http://192.168.253.1:8088/CallName/servlet/AccountServler";
    private static HttpClient httpClient;
    public AccountHttpUtils(HttpClient httpClient) {
           this.httpClient = httpClient;
    }
   public static String sendHttpClient(String path,Map<String,String> map,String encode){
      List<NameValuePair> list = new ArrayList<NameValuePair>();
      if(map != null && !map.isEmpty()){
          for(Map.Entry<String, String> entry : map.entrySet()){//迭代器
              //键值对
              NameValuePair nameValuePair = new BasicNameValuePair(entry.getKey(), entry.getValue());
              list.add(nameValuePair);
          }
      }
      try {
          //实现将请求的参数封装到表单中，
        UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list ,encode);
        //使用post方式提交数据
        HttpPost post = new HttpPost(path);
        post.setEntity(entity);//请求体中
        //默认客户端
        HttpClient client = httpClient;  

        HttpResponse httpResponse = client.execute(post);
        if(httpResponse.getStatusLine().getStatusCode() == 200){
            HttpEntity httpEntity = httpResponse.getEntity();
            InputStream inputStream = httpEntity.getContent();
            return changeInputeStream(inputStream, encode);
        }
    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }  

       return "";
   }
   /**
    * 将一个输入流转换成字符串
    * @param inputStream
    * @param encode
    * @return
    */
   private static String changeInputeStream(InputStream inputStream,String encode) {
       //通常叫做内存流，写在内存中的
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        byte[] data = new byte[1024];
        int len = 0;
        String result = "";
        if(inputStream != null){
            try {
                while((len = inputStream.read(data))!=-1){
                    data.toString();
                    outputStream.write(data, 0, len);
                }
                //result是在服务器端设置的doPost函数中的
                result = new String(outputStream.toByteArray(),encode);
                outputStream.flush();
                outputStream.close();
                inputStream.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return result;
    }
    public static String set(String id,String name,int permission) {
        // TODO Auto-generated method stub
        Map<String, String> map = new HashMap<String, String>();
        map.put("id", id);
        map.put("name", name);
        map.put("permission", String.valueOf(permission));
        String result = AccountHttpUtils.sendHttpClient(AbstractHttpUtils.PATH+"servlet/AccountServler", map, "utf-8");
        System.out.println("result:"+ result);
        return result;
    }  

}

　　4.get请求访问的是百度，返回的是百度首页的源代码

post是我的一个小项目中的类

不过结构已经很清晰啦。。。。

留着备用。。。。。。

http://www.cnblogs.com/jycboy/p/httpclient.html