android学习笔记(13) intent Services多线程初步-蒲公英云

android学习笔记(13) intent Services多线程初步

IntentService是Service类的子类,用来处理异步请求,客户端通过startService(intent)方法传递请求给IntentService,IntentService通过worher thread处理每个Intent对象,执行完所有工作后自动停止Service.

IntentService执行如下操作:
*创建一个与应用程序线程分开的worker thread 用来处理所有通过学习onstartcommand()传递过来的Intent请求
*创建一个work queue,一次只传递一个intent到onHandleIntent()方法中,从而不用担心多线程带来的问题
*当处理完所有请求后自动停止服务,而不需要我们自己调用stopSelf()方法.
*默认实现了onBind()方法,返回值为null
*默认实现了onStartCommand()方法,这个方法将会把我们的intent放到work queue中,然后在onHandleIntent()中执行.
:
写构造方法

复写onHandleIntent()方法

源码对一般的多线程服务和intent service多线程对比:

MainActivity.java：

package com.example1.servicedemo;
import org.apache.commons.logging.Log;
import android.net.sip.SipAudioCall.Listener;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
    protected static final String TAG = "MainActivity";
    private Button btnButton;
    private Button btnButton2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btnButton = (Button)findViewById(R.id.btnstartnormalservice);
        btnButton2 = (Button)findViewById(R.id.btnstartintentservice);
        btnButton.setOnClickListener(listener);
        btnButton2.setOnClickListener(listener);
    }
private OnClickListener listener = new OnClickListener() {
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.btnstartnormalservice:
            Intent intent = new Intent(MainActivity.this,ExampleService.class);
            Log.i(TAG,"主线程ID："+Thread.currentThread().getId());//输出当前线程ID
            startService(intent);
            break;
        case R.id.btnstartintentservice:
            Intent intent2 = new Intent(MainActivity.this,ExampleIntentService.class);
            Log.i(TAG,"主线程ID："+Thread.currentThread().getId());//输出当前线程ID
            startService(intent);
            break;
        default:
            break;
        }
    }
};
}

ExampleIntentService.java

package com.example1.servicedemo;
import android.app.IntentService;
import android.content.Intent;
public class ExampleIntentService extends IntentService {
    private static final String tag = "ExampleIntentService";
    public ExampleIntentService(String name) {
        super("ExampleIntentService");
    }
    @Override
    protected void onHandleIntent(Intent arg0) {
        try {
            android.util.Log.i(tag,"Exampleservice线程ID："+Thread.currentThread().getId());
            android.util.Log.i(tag,"文件下载...");
            Thread.sleep(2000);            
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}