Java callbacks

interface CallBack {                   //declare an interface with the callback methods, so you can use on more than one class and just refer to the interface
    void methodToCallBack();
}

class CallBackImpl implements CallBack {          //class that implements the method to callback defined in the interface
    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();       //because of the interface, the type is Callback even thought the new instance is the CallBackImpl class. This alows to pass different types of classes that have the implementation of CallBack interface
        caller.register(callBack);
    }
}

Source: stackoverflow.com

Similar codes

0 vote319 views1 answer
Exceptions you get in java
Java
0 vote345 views1 answer
Java how to print out a string in uppercase
Java
0 vote333 views1 answer
Instance of keyword in java
Java
5 votes312 views2 answers
Gradle springboot run
Java
0 vote347 views1 answer
Show input dialog java
Java
1 vote326 views1 answer
Java run main of another class
Java
4 votes344 views1 answer
How to check if recyclerview is empty
Java
0 vote315 views2 answers
Enhanced for loop with arraylist
Java
0 vote278 views1 answer
Java remove n from string
Java
-1 vote317 views6 answers
Inheritance in java
Java