判断服务是不是启动了

判断服务是否启动了
package com.tutor.runningservice;
import java.util.List;
import android.app.Activity;
import android.app.ActivityManager;
import android.os.Bundle;
import android.widget.TextView;
public class RunningService extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.main);
        TextView mTextView = new TextView(this);
        ActivityManager mActivityManager =
        (ActivityManager)getSystemService(ACTIVITY_SERVICE);
       
        List<ActivityManager.RunningServiceInfo> mServiceList = mActivityManager.getRunningServices(30);
        //我要判断的服务名字，我在launcher2里加了一个音乐服务  
        final String musicClassName = "com.android.launcher2.MusicService";
             
        boolean b = MusicServiceIsStart(mServiceList, musicClassName);
    
        mTextView.setText("你要判断的服务状态为: " +b+"/n" + getServiceClassName(mServiceList));
        setContentView(mTextView);
    }
    //通过Service的类名来判断是否启动某个服务
    private boolean MusicServiceIsStart(List<ActivityManager.RunningServiceInfo> mServiceList,String className){
   
    for(int i = 0; i < mServiceList.size(); i ++){
    if(className.equals(mServiceList.get(i).service.getClassName())){
    return true;
    }
    }
    return false;
    }
    //获取所有启动的服务的类名
    private String getServiceClassName(List<ActivityManager.RunningServiceInfo> mServiceList){
    String res = "";
    for(int i = 0; i < mServiceList.size(); i ++){
    res+=mServiceList.get(i).service.getClassName()+ " /n";
    }
   
    return res;
    }
}