java 命令模式详解，敢不敢稍微不同一点

你是不是把网上那些命令模式看腻了，千篇一律的抄袭，那个类图不知道是那里画的，明明都错了，那么多人贴上来，代码也直接copy过来。。。我已经无力吐槽了。

我根据自己想法写TV的命令模式例子

干货，上代码

//电视表示接收者类
class TV{
private int currentChannel=0,lastChannel=0;
public void turnon(){
System.out.println("TV ON " + currentChannel);
}
public void turnoff(){
System.out.println("TV OFF");
lastChannel=currentChannel;
currentChannel=0;
}
public void turnChanle(int to){
System.out.println("change channel from "+currentChannel+" to "+ to);
lastChannel=currentChannel ;
currentChannel = to;
}
public void undo(){
turnChanle(lastChannel);
}
}
//抽象的命令类，不同于其他地方说的Command接口 , 感觉可以写一个Commad接口只包含execute方法，然后用TVCommand实现它，有兴趣的可以试试
abstract class TVCommand{
protected TV tv;
public abstract void execute();
}
//一下都是具体的命令类
class TurnOnConcreteTVcommand extends TVCommand{

@Override
public void execute() {
tv.turnon();
}
public TurnOnConcreteTVcommand(TV tv){
this.tv = tv;
}
}
class TurnOffConcreteTVcommand extends TVCommand{

@Override
public void execute() {
tv.turnoff();
}
public TurnOffConcreteTVcommand(TV tv){
this.tv = tv;
}
}
class TurnChannelConcreteTVcommand extends TVCommand{

protected int tochannel;
@Override
public void execute() {
tv.turnChanle(tochannel);
}
public void setTochannel(int tochannel) {
this.tochannel = tochannel;
}
public TurnChannelConcreteTVcommand(TV tv){
this.tv = tv;
}
}
class UndoConcreteTVcommand extends TVCommand{

@Override
public void execute() {
tv.undo();
}
public UndoConcreteTVcommand(TV tv){
this.tv = tv;
}
}
// 遥控器 调用者，和用户交互的接口
class ControlPanel{
private ArrayList<TVCommand> commandArryList = new ArrayList<>();

public void turnon(){
boolean flag= false;
for (TVCommand command :commandArryList){
if (command instanceof TurnOnConcreteTVcommand){
command.execute();
flag=true;
break;
}
}
if (!flag){
alert();
}
}
public void turnoff(){
boolean flag= false;
for (TVCommand command :commandArryList){
if (command instanceof TurnOffConcreteTVcommand){
command.execute();
flag=true;
break;
}
}
if (!flag){
alert();
}
}
public void turnChannel(int to){
boolean flag= false;
for (TVCommand command :commandArryList){
if (command instanceof TurnChannelConcreteTVcommand){
TurnChannelConcreteTVcommand turnChannelConcreteTVcommand = (TurnChannelConcreteTVcommand) command;
turnChannelConcreteTVcommand.setTochannel(to);
turnChannelConcreteTVcommand.execute();
flag=true;
break;
}
}
if (!flag){
alert();
}

}
public void undo(){
boolean flag =false;
for (TVCommand command :commandArryList){
if (command instanceof UndoConcreteTVcommand){
command.execute();
flag=true;
break;
}
}
if (!flag){
alert();
}
}
public void addCommand(TVCommand command){
commandArryList.add(command);
}
private void alert(){
System.out.println("此遥控板不支持此功能");

}
}

class Client1{
public static void main(String[] args) {
//电视
TV tv = new TV();
//具体的命令
TVCommand onCommand = new TurnOnConcreteTVcommand(tv);
TVCommand offCommand = new TurnOffConcreteTVcommand(tv);
TVCommand turnChannelCommand = new TurnChannelConcreteTVcommand(tv);
TVCommand undoCommand = new UndoConcreteTVcommand(tv);
//将命令加入到遥控器上，相当于所有的命令组合在一起形成了一个遥控器
ControlPanel controlPanel = new ControlPanel();
controlPanel.addCommand(onCommand);
controlPanel.addCommand(offCommand);
controlPanel.addCommand(turnChannelCommand);
//controlPanel.addCommand(undoCommand);
//直接点击遥控器上的按钮
controlPanel.turnon();
//具体的点击的时候才选择切换到 XX 频道
controlPanel.turnChannel(20);
controlPanel.turnChannel(30);
controlPanel.turnChannel(40);
controlPanel.undo();
controlPanel.turnoff();
controlPanel.turnon();

}

在Invoker类上，我写了很多操作，我不知道这样是对是错，欢迎指正！