《安卓网络编程》之第三篇 使用Apache接口

在Android系统中，提供了一下三种通信接口：

•  标准的Java 接口：java.net
• Apache接口：org.apache.http
• Android网络接口：android.net.http

在android系统中，包含了Apache HttpClient库，此库为执行Android中的网络操作之首选方法。

Apache应用基础

本文讲的Apache是一个中介，它只负责传递消息，至于具体怎么上网它概不负责。

联网流程

　　在Android系统中，可以采用HttpPost和HttpGet来封装Post请求和Get请求，然后再使用HttpClient的excute()方法发送Post或者get请求来返回服务器的响应数据。使用Apache联网的基本流程如下：

1. 设置连接和读取超时时间，并建立HttpClient对象
2. 实现Get请求
3. 实现Post发送请求处理
4. 使用Response响应请求

这样，使用Apache实现联网处理数据交互的过程就完成了，无论多么复杂的项目，都必须遵循上面的流程。

下面是一个运行在安卓上的工程实例：

package irdc.httpSHI;


/*必需引用apache.http相关类来建立HTTP联机*/
import org.apache.http.HttpResponse; 
import org.apache.http.NameValuePair; 
import org.apache.http.client.ClientProtocolException; 
import org.apache.http.client.entity.UrlEncodedFormEntity; 
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.apache.http.message.BasicNameValuePair; 
import org.apache.http.protocol.HTTP; 
import org.apache.http.util.EntityUtils; 
/*必需引用java.io 与java.util相关类?来读写档案*/
import irdc.httpSHI.R;

import java.io.IOException; 
import java.util.ArrayList; 
import java.util.List; 
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 

public class httpSHI extends Activity 
{ 
  /*宣╳两个Button物件,与几个TextView物件*/
  private Button mButton1,mButton2; 
  private TextView mTextView1; 
   
  /** Called when the activity is first created. */ 
  @Override 
  public void onCreate(Bundle savedInstanceState) 
  { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
     
    /*透过findViewById建构巳建立TextView与Button对象*/ 
    mButton1 =(Button) findViewById(R.id.myButton1); 
    mButton2 =(Button) findViewById(R.id.myButton2);
    mTextView1 = (TextView) findViewById(R.id.myTextView1); 
     
    mButton1.setOnClickListener(new Button.OnClickListener() 
    { 
  
      @Override 
      public void onClick(View v) 
      { 
   
        String uriAPI = "http://www.baidu.com";
        /*建立HTTP Post联机*/
        HttpPost httpRequest = new HttpPost(uriAPI); 
        /*
         * Post传送变量必须用NameValuePair[]存储
        */
        List <NameValuePair> params = new ArrayList <NameValuePair>(); 
        params.add(new BasicNameValuePair("str", "I am Post String")); 
        try 
        { 
          /*发叨HTTP request*/
          httpRequest.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8)); 
          /*取得HTTP response*/
          HttpResponse httpResponse = new DefaultHttpClient().execute(httpRequest); 
          /*若状态码为200*/
          if(httpResponse.getStatusLine().getStatusCode() == 200)  
          { 
            /*获取字符串*/
            String strResult = EntityUtils.toString(httpResponse.getEntity()); 
            mTextView1.setText(strResult); 
          } 
          else 
          { 
            mTextView1.setText("Error Response: "+httpResponse.getStatusLine().toString()); 
          } 
        } 
        catch (ClientProtocolException e) 
        {  
          mTextView1.setText(e.getMessage().toString()); 
          e.printStackTrace(); 
        } 
        catch (IOException e) 
        {  
          mTextView1.setText(e.getMessage().toString()); 
          e.printStackTrace(); 
        } 
        catch (Exception e) 
        {  
          mTextView1.setText(e.getMessage().toString()); 
          e.printStackTrace();  
        }  
         
      } 
    }); 
    mButton2.setOnClickListener(new Button.OnClickListener() 
    { 
      @Override 
      public void onClick(View v) 
      { 
        // TODO Auto-generated method stub 
        String uriAPI = "http://www.baidu.com/str=I+am+Get+String"; 
        /*建立HTTP Get联机*/
        HttpGet httpRequest = new HttpGet(uriAPI); 
        try 
        { 
          /*发送获取的HTTP request*/
          HttpResponse httpResponse = new DefaultHttpClient().execute(httpRequest); 
          /*若状态码为200*/
          if(httpResponse.getStatusLine().getStatusCode() == 200)  
          { 
            /*取叨并应?串*/
            String strResult = EntityUtils.toString(httpResponse.getEntity());
            strResult = eregi_replace("(
|
|
|

)","",strResult);
            mTextView1.setText(strResult); 
          } 
          else 
          { 
            mTextView1.setText("Error Response: "+httpResponse.getStatusLine().toString()); 
          } 
        } 
        catch (ClientProtocolException e) 
        {  
          mTextView1.setText(e.getMessage().toString()); 
          e.printStackTrace(); 
        } 
        catch (IOException e) 
        {  
          mTextView1.setText(e.getMessage().toString()); 
          e.printStackTrace(); 
        } 
        catch (Exception e) 
        {  
          mTextView1.setText(e.getMessage().toString()); 
          e.printStackTrace();  
        }  
      } 
    }); 
  }
    public String eregi_replace(String strFrom, String strTo, String strTarget)
    {
      String strPattern = "(?i)"+strFrom;
      Pattern p = Pattern.compile(strPattern);
      Matcher m = p.matcher(strTarget);
      if(m.find())
      {
        return strTarget.replaceAll(strFrom, strTo);
      }
      else
      {
        return strTarget;
      }
    }
} 

实现了post和get俩种方式联网。

xml文件：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout 
  xmlns:android="http://schemas.android.com/apk/res/android" 
  android:background="@drawable/white" 
  android:orientation="vertical" 
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent" 
  > 
  <TextView 
    android:id="@+id/myTextView1" 
    android:layout_width="fill_parent"  
    android:layout_height="wrap_content"  
    android:text="@string/title"/> 
  <Button 
    android:id="@+id/myButton1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="@string/str_button1" /> 
    <Button 
    android:id="@+id/myButton2" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="@string/str_button2" />    
</LinearLayout>