CODEWITHSUNDEEP
javaandroidindexoutofboundsexceptionarray-map
omri tal
omri tal

Reputation: 98

Java ArrayIndexOutOfBounds Exception on array map

I have a code that iterates on ArrayMap keys, and I got an Array Index Out Of Bounds Exception from unknown reason

From Crashalytics:

Fatal Exception: java.lang.ArrayIndexOutOfBoundsException
length=56; index=56
android.util.ArrayMap$1.colGetEntry (ArrayMap.java:763)
android.util.MapCollections$ArrayIterator.next (MapCollections.java:55)

The code looks like that:

private ArrayMap<String,RequestData> handlers = new ArrayMap<>();

public void removeAllHandlers() {
    synchronized (handlers) {
        for (String s : handlers.keySet()) {
            handlers.remove(s);
        }
    }
}

the Exception happened at this line: for (String s : handlers.keySet())

Any clue what am I doing wrong?

Upvotes: 0

Views: 1232

Answers (4)

Hearen
Hearen

Reputation: 7838

Just as others mentioned, you cannot remove(Object o) in a for loop, you have to do that removal using Iterator as

public void removeAllHandlers() {
    synchronized (handlers) {
            Iterator<String> keyIterator = handlers.keySet().iterator();
            while (keyIterator.hasNext()) {
                 RequestData requestData = handlers.get(keyIterator.next());
                 if(iDontWant(requestData)) {
                     keyIterator.remove();
                 }
            }
    }
}

Upvotes: 0

Alan Deep
Alan Deep

Reputation: 2105

You cannot remove from a Map or a List while iterating. Use the internal clear method of the Map/List. For instance, handlers.clear();

Code:

private ArrayMap<String,RequestData> handlers = new ArrayMap<>();

public void removeAllHandlers() {
        synchronized (handlers) {
                handlers.clear();
        }
    }

Upvotes: 2

Faruk Yazici
Faruk Yazici

Reputation: 2404

You are modifying the ArrayMap that your are iterating over. This is an anti-pattern in Java and will cause error. I recommend you using another ArrayMap for your modifications.

Upvotes: 0

Ertuğrul &#220;ng&#246;r
Ertuğrul &#220;ng&#246;r

Reputation: 211

Try this

private ArrayMap<String,RequestData> handlers = new ArrayMap<>();

public void removeAllHandlers() {
    synchronized (handlers) {
        ArrayMap<String,RequestData> tempHandlers = handlers;
        for (String s : tempHandlers.keySet()) {
            handlers.remove(s);
        }
    }
}

Upvotes: 0

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