Java命令设计模式优雅解耦命令和执行提高代码可维护性

public interface Command {
    /**
     * 执行
     */
    void execute();
    /**
     * 撤销
     */
    void undo();
}

public class ConcreteCommand1 implements Command {
    private Receiver receiver;
    private boolean isExecute;
    public ConcreteCommand1(Receiver receiver) {
        this.receiver = receiver;
    }
    /**
     * 执行
     */
    @Override
    public void execute() {
        receiver.action1();
        isExecute = true;
    }
    /**
     * 撤销
     */
    @Override
    public void undo() {
        if (isExecute) {
            receiver.undoAction1();
            isExecute = false;
        }
    }
}
public class ConcreteCommand2 implements Command {
    private Receiver receiver;
    private boolean isExecute;
    public ConcreteCommand2(Receiver receiver) {
        this.receiver = receiver;
    }
    /**
     * 执行
     */
    @Override
    public void execute() {
        receiver.action2();
        isExecute = true;
    }
    /**
     * 撤销
     */
    @Override
    public void undo() {
        if (isExecute) {
            receiver.undoAction2();
            isExecute = false;
        }
    }
}

public class Receiver {
    public void action1() {
        System.out.println("Receiver.action1() 被调用...");
    }
    public void action2() {
        System.out.println("Receiver.action2() 被调用...");
    }
    public void undoAction1(){
        System.out.println("Receiver.undoAction1() 被调用...");
    }
    public void undoAction2(){
        System.out.println("Receiver.undoAction2() 被调用...");
    }
}

public class Invoker {
    private List<Command> commandList = new ArrayList<>();
    /**
     * 添加命令
     *
     * @param command
     */
    public void addCommand(Command command) {
        commandList.add(command);
    }
    /**
     * 执行命令
     */
    public void executeCommands() {
        commandList.forEach(Command::execute);
    }
    /**
     * 撤销命令
     */
    public void undoCommands() {
        for (int i = commandList.size() - 1; i >= 0; i--) {
            commandList.get(i).undo();
        }
    }
}

public class Demo {
    public static void main(String[] args) {
        Receiver receiver = new Receiver();
        Command command1 = new ConcreteCommand1(receiver);
        Command command2 = new ConcreteCommand2(receiver);
        Invoker invoker  = new Invoker();
        invoker.addCommand(command1);
        invoker.addCommand(command2);
        invoker.executeCommands();
        invoker.undoCommands();
    }
}