Android中进行HTTP操作

要使自己的Android程序进行http操作，就必须现在AndroidManifest.xml定义访问Internet的权限：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.ncs.hj"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="8" />
	<uses-permission android:name="android.permission.INTERNET"/>
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".HttpTestActivity"
                  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>

下面是布局文件，layout/main.xml

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

下面是Activity的代码：

package com.ncs.hj;

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.client.DefaultHttpClient;

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

public class HttpTestActivity extends Activity {
    /** Called when the activity is first created. */
	Button btn =null;
	HttpResponse httpResponse = null;
	HttpEntity httpEntity = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        btn = (Button)findViewById(R.id.btn);
        btn.setOnClickListener(new HttpTest());
    }
    
    class HttpTest implements OnClickListener {
		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			HttpGet httpGet = new HttpGet("http://www.google.com");
			HttpClient httpClient = new DefaultHttpClient();
			InputStream inputStream = null;
			try {
				httpResponse = httpClient.execute(httpGet);
				httpEntity = httpResponse.getEntity();
				inputStream = httpEntity.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 (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
    }
}