java中实现回调callback

Define an interface, and implement it in the class that will receive the callback.

Have attention to the multi-threading in your case.

Code example from  %E5%A4%9A%E7%BA%BF%E7%A8%8B/java-callback.html

interface CallBack {
    void methodToCallBack();
}

class CallBackImpl implements CallBack {
    public void methodToCallBack() {
        System.out.println("I've been called back");
    }
}

class Caller {

    public void register(CallBack callback) {
        callback.methodToCallBack();
    }

    public static void main(String[] args) {
        Caller caller = new Caller();
        CallBack callBack = new CallBackImpl();
        caller.register(callBack);
    }
}