[medium snippets] #medium #designPattern #CommandPattern

command-patterns-java8.java

public interface Command {
  void execute();
}

public class ClientMain {
  static public void main(String[] args) {
    ReceiverA receiverA = new ReceiverA();
    ReceiverB receiverB = new ReceiverB();
    
    Invoker invoker = new Invoker();
    invoker.setCommand(0, receiverA::doAction); 
    invoker.setCommand(1, receiverB::doAction); 
    
    invoker.onButtonWasPushed(0);
    invoker.onButtonWasPushed(1);
    invoker.onButtonWasPushed(1);
  }
}