设计模式之命令模式

package com.hml.command;

public abstract class Command {

    protected Receiver receiver;

    public Command(Receiver receiver) {
        this.receiver = receiver;
    }
    
    public abstract void excute();
    
}

package com.hml.command;

public class ConcretaeCommand extends Command {

    public ConcretaeCommand(Receiver receiver) {
        super(receiver);
    }

    @Override
    public void excute() {
        receiver.action();
    }

}

package com.hml.command;

/**
 * 该类知道如何去处理命令 ，不同的命令可以有不同的Receiver
 */
public class Receiver {

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

}

package com.hml.command;

public class Invoker {
    private Command command;

    public Command getCommand() {
        return command;
    }

    public void setCommand(Command command) {
        this.command = command;
    }
    
    public void excute() {
        command.excute();
    }
}

package com.hml.command;

public class Test {
    public static void main(String[] args) {
        Receiver r = new Receiver();
        Command command = new ConcretaeCommand(r);
        Invoker i = new Invoker();
        i.setCommand(command);
        i.excute();

    }
}