How do I implement the Command Pattern in Java?

How do I implement the Command Pattern in Java?

The Command Pattern is a behavioral design pattern that turns a request into a stand-alone object. This allows for parameterization of clients with queues, requests, and operations. Would you like a code example?

Yes, please provide a code example.

Sure! Here's a simple example:

// Command Interface
interface Command {
    void execute();
}

// Concrete Command
class LightOnCommand implements Command {
    Light light;
    public LightOnCommand(Light light) {
        this.light = light;
    }
    public void execute() {
        light.turnOn();
    }
}

// Receiver
class Light {
    public void turnOn() {
        System.out.println("The light is on");
    }
}

// Invoker
class RemoteControl {
    Command command;
    public void setCommand(Command command) {
        this.command = command;
    }
    public void pressButton() {
        command.execute();
    }
}

// Client
public class Main {
    public static void main(String[] args) {
        Light light = new Light();
        Command lightOn = new LightOnCommand(light);
        RemoteControl remote = new RemoteControl();
        remote.setCommand(lightOn);
        remote.pressButton();
    }
}

This code demonstrates how to use the Command Pattern to control a light.

What are the benefits of using the Command Pattern?

The Command Pattern provides several benefits:

1. Decouples the sender and receiver of a request.
2. Supports undoable operations.
3. Enables logging of requests.
4. Allows for queuing of requests.