CODEWITHSUNDEEP
javaandroid
Priyan RockZ
Priyan RockZ

Reputation: 1615

How to resolve this error in android - java.lang.RuntimeException: Only one Looper may be created per thread

here is my code in background service 

public class BackgroundService extends Service {
    private int interval1 = 60; // 60 seconds
    private int interval2 = 60; // 60 seconds
    //=============================================================================================================================
    private Handler mTimer1 = new Handler();
    private Runnable mTask1 = new Runnable() {
        public void run() {
            Looper.prepare();
            Log.w("GPS Tracker", "Tracker going to run "+new Date());
            LocationManager mlocManager =(LocationManager)getSystemService(Context.LOCATION_SERVICE);
            LocationListener mlocListener = new MyLocationListener();
            mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);//, Looper.getMainLooper()); 
            mTimer1.postDelayed(this, interval1 * 1000L);
            Looper.loop(); 
        }
    };


//=============================================================================================================================
    private Handler mTimer2 = new Handler();
    private Runnable mTask2 = new Runnable() {
        public void run() {
            if (isOnline() == true) {
                Log.w("Method 2", "setUpdateCardAcceptTag");
                setUpdateCardAcceptTag();
                Log.w("Method 3", "getCardBulkSerialData");
                getCardBulkSerialData();
                Log.w("Method 12", "updateStockDataFromRemote");
                updateStockDataFromRemote();
                Log.w("Method 5", "SetRemarksData");
                SetRemarksData();
                Log.w("Method 6", "SetCardSaleData");
                SetCardSaleData();
                Log.w("Method 7", "synchMerchants");
                synchMerchants();
                Log.w("Method 9", "getUpdatedCities");
                getUpdatedCities();
                Log.w("Method 10", "getNotifications");
                getNotifications();
                Log.w("Method 11", "getNextSerialDetails");
                getNextSerialDetails();
                Log.w("Method 12", "getNextSerialDetails");
                //synchLocations();
                Log.w("Method 13", "synchLocations");

            }
            mTimer2.postDelayed(this, interval2 * 1000L);
        }
    };

when i run the application its stopped after few seconds.its says below error message in log console please help me to sort out this issue

thanks

Upvotes: 2

Views: 1317

Answers (3)

tianwei
tianwei

Reputation: 1879

Because when a activity or a service(both of them extends ContextWrapper which extends Context)is created by android,a Loopper object will be created also.

In your code ,you use Looper.prepare(); But what does it really do?

public static void prepare() {
    prepare(true);
}

private static void prepare(boolean quitAllowed) {
    if (sThreadLocal.get() != null) {
        throw new RuntimeException("Only one Looper may be created per thread");
    }
    sThreadLocal.set(new Looper(quitAllowed));
}

(You can find this code in Looper.java)

Because the android os has invoke the mLooper.prepare(); method at the time the service is created,so the sThreadLocal has a Looper object.When your code is executed,the RuntimeException will be thrown.

Upvotes: 3

Marcel Tricolici
Marcel Tricolici

Reputation: 440

Handler runs the 'runnable' in the thread where Handler has been created. You have 2 handlers.. they are in the same thread. I guess they are in main thread .. and main thread already has a looper.. Try to remove "Looper.Prepare" and "Looper.Loop" calls.

Upvotes: 1

Gopal Gopi
Gopal Gopi

Reputation: 11131

You can not prepare the Looper multiple times for a Thread. before preparing, Chcek whether Looper is associated with that Thread or not.

private Runnable mTask1 = new Runnable() {
    public void run() {
        if(Looper.myLooper() == null) { // check already Looper is associated or not.
           Looper.prepare(); // No Looper is defined So define a new one
        }
        Log.w("GPS Tracker", "Tracker going to run "+new Date());
        LocationManager mlocManager =(LocationManager)getSystemService(Context.LOCATION_SERVICE);
        LocationListener mlocListener = new MyLocationListener();
        mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);//, Looper.getMainLooper()); 
        mTimer1.postDelayed(this, interval1 * 1000L);
        Looper.loop(); 
    }
};

Upvotes: 4

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