Question

I created a little android game but I am getting weird error.

Here is log:

    12-31 16:10:22.407: E/AndroidRuntime(12824): FATAL EXCEPTION: Thread-1461
    12-31 16:10:22.407: E/AndroidRuntime(12824): java.lang.IndexOutOfBoundsException: Invalid index 1, size is 0
    12-31 16:10:22.407: E/AndroidRuntime(12824):    at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:251)
    12-31 16:10:22.407: E/AndroidRuntime(12824):    at java.util.ArrayList.get(ArrayList.java:304)
    12-31 16:10:22.407: E/AndroidRuntime(12824):    at **.***.****.GameScreen.updatePaused(GameScreen.java:91)
    12-31 16:10:22.407: E/AndroidRuntime(12824):    at **.***.****.GameScreen.update(GameScreen.java:43)
    12-31 16:10:22.407: E/AndroidRuntime(12824):    at **.***.****.framework.impl.AndroidFastRenderView.run(AndroidFastRenderView.java:39)
    12-31 16:10:22.407: E/AndroidRuntime(12824):    at java.lang.Thread.run(Thread.java:856)

And here is part of code executed :

    int len = touchEvents.size();
    for(int i = 0; i < len; i++) {
        TouchEvent event = touchEvents.get(i); ->>> this line
    .
    .
    .

What is wrong ?

Answer 1

If you are having threading issues you’ll have to either synchronize on the collection prior to looping like this

synchronize(touchEvents) {
    for(TouchEvent event : touchEvents) {
        //do whatever you want with events
    }
}

Or, you can make a local copy of the collection and loop over that, if it’s still valid to process events in the collection if they have been removed while you’re working on the copy.