命令模式

命令模式通常包含下面几个角色：

1、Client：创建一个命令，并决定接受者

2、Command：命令接口，定义一个抽象方法

3、ConcreteCommand：具体命令，负责调用接受者的相应操作

4、Invoker：请求者，负责调用命令对象执行请求，调用者可能会对在调用时加入自己需求

5、Receiver：接受者，负责具体实施和执行一次请求

Client

package design.pattern.command;

public interface Command {
    public void execute();
}

Command

package design.pattern.command;

public interface Command {
    public void execute();
}

Receiver

package design.pattern.command;

public interface Receiver {
    public void action();
}

ConcreteConmmand

package design.pattern.command;

public class ConcreteCommand implements Command {
    private Receiver receiver;
    
    public ConcreteCommand(Receiver receiver) {
        this.receiver = receiver;
    }
    @Override
    public void execute() {
        receiver.action();
    }

}

ConcreteReceiver

package design.pattern.command;

public class ConcreteReceiver implements Receiver {

    @Override
    public void action() {
        System.out.println("action");
    }
    
}