列出Android装置中所有启动的服务，及判断某个服务是否开启

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;      }  }