设计模式-命令模式

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前言

Linus Benedict Torvalds : RTFSC – Read The Funning Source Code

概述

将一个请求封装成一个对象，从而让用户使用不同的请求把客户端参数化；对请求排队或者记录请求日志，以及支持可撤销的操作。

优点：可以对代码进行强解耦，保持开闭原则。
缺点：类会变得很臃肿，要小心使用。

代码

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public class Receiver {
    public void action() {
        System.out.println("Receiver action");
    }
}
public interface Command {
    void execute();
}
public class ConcreteCommand implements Command {
    private Receiver receiver;
    public ConcreteCommand(Receiver receiver) {
        this.receiver = receiver;
    }
    @Override
    public void execute() {
        receiver.action();
    }
}
public class Invoker {
    private Command command;
    public Invoker(Command command) {
        this.command = command;
    }
    public void action() {
        command.execute();
    }
}
public static void main() {
    Receiver receiver = new Receiver();
    Command command = new ConcreteCommand(receiver);
    Invoker invoker = new Invoker(command);
    invoker.action();
}

设计模式 目录