CODEWITHSUNDEEP
javaevents
user1424119
user1424119

Reputation: 121

Java remove listener, when callback is executed

I just can't figure out how to remove listener when I have some event executed. I have some leaking issue using websockets, and this can probaly fix it.

final WebSocket w = asyncHttpClient.prepareGet(url)
    .execute(new WebSocketUpgradeHandler.Builder().build())
    .get();

w.addWebSocketListener(new WebSocketTextListener() {

    public void onMessage(String message) {
        listener.onMessage(responseMessage);
        // Here is the place I want to do my w.removeWebSocketListener(l);
    }

    @Override
    public void onFragment(String s, boolean b) {
    }

    public void onOpen(WebSocket websocket) {
    }

    @Override
    public void onClose(WebSocket webSocket) {
    }

    @Override
    public void onError(Throwable throwable) {
    }

});

The problem is when I create WebSocketTextListener lis = new .... and passing in there is something like one object need other object and other object is dependent on this, and I'm still now allowed to do what I want.
Looks like it is something simple, but can't figure out.

Upvotes: 0

Views: 1829

Answers (2)

user1424119
user1424119

Reputation: 121

Using "this" in anonumous inner class is the way to solve problem. But, it is muck better to refactor code, to avoid using anonumous classes, for testability and better understanding.

Upvotes: 1

Jens Egholm
Jens Egholm

Reputation: 2710

Normally event listeners can be removed with a removeXXXListener method. But it requires that you provide the exact same event listener instance as parameter. You can store the event listener and later remove it using the same reference. But since you, in the onMessage message already are inside the scope of the event listener, using this should work.

Try something like 

listener.onMessage(responseMessage);
// Here is the place I want to do my w.removeWebSocketListener(l);
w.removeWebSocketListener(this);

Upvotes: 1

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