android 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