设计模式之命令模式

命令模式：将一个请求封装为一个对象，从而可以用不同的请求对客户进行参数化；对请求排队或记录请求日志，以及支持可撤销的操作。

 

public abstract class Command {
    protected Receiver receiver;

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

    public abstract void execute();
}

 

public class ConcreteCommand extends Command {
    public ConcreteCommand(Receiver receiver) {
        super(receiver);
    }

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

 

public class Receiver {
    public void action() {
        System.out.println("执行请求！");
    }
}

 

public class Invoker {
    private Command command;

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

    public void executeCommand() {
        command.execute();
    }
}

 

public class CommandDemo {
    public static void main(String[] args) {
        Receiver receiver = new Receiver();
        Command command = new ConcreteCommand(receiver);

        Invoker invoker = new Invoker();
        invoker.setCommand(command);
        invoker.executeCommand();
    }
}