Android 利用Service实现下载网络图片至sdk卡

package com.example.myapp5;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
/**
 * Android 利用service实现下载图片功能
 * @author shaobn
 * @date 2015-9-14
 * @packege com.example.myapp5.MyApp5
 */
public class MainActivity extends Activity {
    private Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button) this.findViewById(R.id.button1);
        button.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                Intent intent = new Intent(MainActivity.this,MyService.class);
                startService(intent);
            }
        });
    }    
}

package com.example.myapp5;

import java.io.File;
import java.io.FileOutputStream;

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 org.apache.http.util.EntityUtils;

import android.app.Service;
import android.content.Intent;
import android.os.Environment;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.widget.Toast;

public class MyService extends Service {
    private final static String IMAGEPAH = "https://www.baidu.com/img/bd_logo1.png";
    @Override
    public void onCreate() {
        // TODO Auto-generated method stub
        super.onCreate();
    }
    @Override
    public IBinder onBind(Intent arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // TODO Auto-generated method stub
        final Handler handler = new Handler(){
            
            public void handleMessage(android.os.Message msg) {
                if(msg.what==1){
                    Toast.makeText(getApplicationContext(), "关闭了", 1).show();
                    stopSelf();
                }        
            };
            
        };
        new Thread(new Runnable() {
            
            @Override
            public void run() {
                // TODO Auto-generated method stub
                HttpClient httpClient = new DefaultHttpClient();
                HttpGet httpGet = new HttpGet(IMAGEPAH);
                HttpResponse httpResponse = null;
                File file = Environment.getExternalStorageDirectory();
                File file2 = null;
                FileOutputStream fos = null;
                try {
                httpResponse =httpClient.execute(httpGet);
                if (httpResponse.getStatusLine().getStatusCode()==200) {
                    byte[] num = EntityUtils.toByteArray(httpResponse.getEntity());
                    if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
                        file2 = new File(file, "/Movies/a.jpg");
                        file2.createNewFile();
                        fos = new FileOutputStream(file2);
                        fos.write(num);
                        Message message = Message.obtain();
                        message.what = 1;
                        handler.sendMessage(message);
                    }
                }
                    
                } catch (Exception e) {
                    e.printStackTrace();// TODO: handle exception
                }finally{
                    if(fos!=null){
                        try {
                            fos.close();
                        } catch (Exception e2) {
                            // TODO: handle exception
                            e2.printStackTrace();
                        }
                    }
                
                }
                
            }
        }).start();
        return super.onStartCommand(intent, flags, startId);
    }
    @Override
    public void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
    }
}