Question

我在服务文件（backgroundService.java）中声明了一个静态Arraylist 变量。我收到推送消息（使用GCM）后，我正在更新静态变量。我正在使用4.0.4设备（三星S3）..静态变量变空，一旦我的应用程序进入后台，然后如果我长按memu按钮并刷我的应用程序（一旦我们刷了应用程序已完成但没有强制停止），服务暂停一段时间再次启动，即不调用服务onDestroy方法而是OnCreate方法在该暂停之后.. 在该暂停之后，静态ArrayList变为空。怎么解决？我不希望我的静态Arraylist失去价值..

仅在Android版本4.0+设备中出现此问题。

public class BackgroundService extends Service

{ private Timer timer = new Timer（）;

Context mContext;

String LOG_TAG=BackgroundService.class.getSimpleName();
    ApplicationInfo ai;
    private static boolean isRunning = false; 
public static ArrayList<String> mDMPush=new ArrayList<String>();

@Override
public void onCreate() 
{
      super.onCreate();
      Log.e(LOG_TAG,"on create ");
      isRunning = true; 


}


@Override
public void onStart(Intent intent, int startId) {

    super.onStart(intent, startId);  


    Log.e(LOG_TAG,"mDMPush"+mDMPush);

    Log.e(LOG_TAG,"mDMPush outside if else "+mDMPush.size()+"   "+mDMPush.isEmpty());
            startService();



}

public static boolean isRunning() 
{ 
    return isRunning; 
} 

private void startService()
{        
   int delay = 100;
   int period =500;
final PackageManager pm = getPackageManager();

   timer.scheduleAtFixedRate(new TimerTask() {
       public void run() 
       {

        ActivityManager am = (ActivityManager) mContext.getSystemService(Activity.ACTIVITY_SERVICE);
        String packageName = am.getRunningTasks(1).get(0).topActivity.getPackageName();
        try {
                 ai = pm.getApplicationInfo(packageName, 0);
                 if ((ai.flags & ApplicationInfo.FLAG_SYSTEM) != 0) {


                       **Iam doing an action inside this timer using that arraylist mDMPush.. I ll add value to the arraylist once i received a push***              

                 }
           } catch (NameNotFoundException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
           }



       }
     }, delay, period);

}

Answer 1

看起来您的应用程序进程被杀死并重新创建，这在Android上是正常的事情。您不应该依赖静态，将其保存到更多持久性存储，如首选项或db。

Answer 2

您应该查看此页面以找到更好的方法来实现数组列表的存储Android Persistent Storage

Answer 3

这是如何在持久存储中保存数组列表的

  Set<String> localStore = new HashSet<String>();
            List<String> list = new ArrayList<String>();
    localStore.addAll(list);
    SharedPreferences ssidPref = getSharedPreferences("ssidPref", Context.MODE_PRIVATE);
                SharedPreferences.Editor EDITIOR = ssidPref.edit();
                EDITIOR.putStringSet("ssidStored", localStore);
                EDITIOR.commit();

阅读

localStore = ssidPref.getStringSet("ssidStored", null);

Android：Static Arraylist在服务中变得空洞

3 个答案: