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 vote348 views1 answer
Spring boot procfile run profile
Java Spring
22 votes290 views2 answers
Java quit application
Java
183 votes450 views6 answers
Last element of an array
Java
0 vote367 views1 answer
Execution repackage of goal org.springframework.boot:spring-boot-maven-plugin:2.5.0:repackage failed:
Java Spring
0 vote274 views1 answer
Group all keys with same values in a hashmap java
Java
0 vote279 views1 answer
Java generate secure random password
Java
0 vote258 views1 answer
Java gmt zoneid
Java
0 vote257 views1 answer
Find subarray with given sum
Java
0 vote272 views1 answer
Print values of bst java
Java
10 votes293 views4 answers
Java capitalize first letter of each word
Java