服务端怎样暴露IBinder接口对象

服务端怎样暴露IBinder接口对象：

package com.example.mydownload; 
 
import android.app.Service; 
import android.content.Intent; 
import android.os.Binder; 
import android.os.IBinder; 
import android.util.Log; 
 
//实现接口中的方法 
	  
public class MyService extends Service { 
	//接口对象 
	IBinder mybBinder = new MyBinder(); 
	 
	class MyBinder extends Binder{ 
		public String helloWorld(String name){ 
			return name; 
		} 
	} 
	 
	@Override 
	public void onCreate() { 
		Log.e("log", "onCreate"); 
		super.onCreate(); 
	} 
 
 
	@Override 
	public void onDestroy() { 
		Log.e("log", "onDestroy"); 
		super.onDestroy(); 
	} 
 
 
	@Override 
	public int onStartCommand(Intent intent, int flags, int startId) { 
		Log.e("log", "onStartCommand"); 
		return super.onStartCommand(intent, flags, startId); 
	} 
 
	 
	@Override 
	public IBinder onBind(Intent arg0) { 
		return mybBinder; 
	} 
 
}