HttpClient ：發起Http連線請求的物件，
HttpResponse ：Http 請求返回的響應。

總的設計思路如下：

傳送請求：(HttpResponse)response=(HttpClient)client.execute((HttpGet)request);
獲取響應資料：response.getEntity().getContent();

簡單的示例舉例如下，主要實現獲取www.baidu.com的內容： 特別注意要在AndroidManifest.xml新增訪問網路的許可權！！！

MainActivity.java

package com.android.httpclient;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URI;
import java.net.URISyntaxException;

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

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

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
	private Button btn;
	private TextView tv;
	private String content = null;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        btn = (Button) findViewById(R.id.button1);
        tv = (TextView) findViewById(R.id.textView1);
        btn.setOnClickListener(new OnClickListener(){

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				HttpClient client = new DefaultHttpClient();
				HttpGet request = new HttpGet("http://www.baidu.com/");
				try{
					HttpResponse response = client.execute(request);
					BufferedReader reader = new BufferedReader(new InputStreamReader(
							response.getEntity().getContent()));
					for(String s = reader.readLine(); s != null; s = reader.readLine()){
						content += s;
					}
					tv.setText(content);
				}catch (Exception e){
					e.printStackTrace();
				}
			}
        	
        });
        
    }
}


 

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<Button 
	android:text="Button" 
	android:id="@+id/button1" 
	android:layout_width="wrap_content" 
	android:layout_height="wrap_content">
</Button>
<TextView 
	android:text="TextView" 
	android:id="@+id/textView1" 
	android:layout_width="wrap_content" 
	android:layout_height="wrap_content">
</TextView>
</LinearLayout>
 

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.android.httpclient"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="1" />
	<uses-permission android:name="android.permission.INTERNET"/>
 
	
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".MainActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
    
</manifest>