/** *//**
* @author LX
* 通用Reveiver類
*/
public abstract class Receiver 
{
//抽象接收者，定義每個(gè)接收者必須完成的業(yè)務(wù)
public abstract void doSomething();
//撤銷
public abstract void undo();
}
/** *//**
*抽象Command類
**/
public abstract class Command {
public abstract void execute();
public abstract void undo();
}
/** *//**
*調(diào)用者類
**/
public class Invoker {
private Command command;
public void setCommand(Command command){
this.command=command;
}
public void action(){
this.command.execute();
}
}
/** *//**
*具體接收者
**/
public class ConcreteReceiver1 extends Receiver {
@Override
public void doSomething() {
}
@Override
public void undo() {
}
}
/** *//**
*具體Command類
**/
public class ConcreteCommand1 extends Command {
private Receiver receiver;
public ConcreteCommand1(Receiver receiver){
this.receiver=receiver;
}
@Override
public void execute() {
receiver.doSomething();
}
@Override
public void undo() {
receiver.undo();
}
}
/** *//**
*測試類
**/
public class Test {
public static void main(String[] args) {
Invoker invoker = new Invoker();
Receiver receiver = new ConcreteReceiver1(); //定義接收者
Command command = new ConcreteCommand1(receiver);//定義一個(gè)發(fā)送給接收者的命令
invoker.setCommand(command);//把命令交給調(diào)用者去執(zhí)行
invoker.action();
}
}
//更完美的Command類
public abstract class Command {
//定義一個(gè)子類的全局共享變量
protected final Receiver receiver;
//實(shí)現(xiàn)類必須定義一個(gè)接收者
public Command(Receiver receiver){
this.receiver=receiver;
}
//每個(gè)命令類都必須有一個(gè)執(zhí)行命令的方法
public abstract void execute();
}
public class ConcreteCommand1 extends Command{
//設(shè)置自己的默認(rèn)構(gòu)造
public ConcreteCommand1(){
super(new ConcreteReceiver1());
}
//設(shè)置新的接收者
public ConcreteCommand1(Receiver receiver) {
super(receiver);
}
//業(yè)務(wù)處理
@Override
public void execute() {
super.receiver.doSomething();
}
}
public class Test {
public static void main(String[] args) {
Invoker invoker = new Invoker();
Command command = new ConcreteCommand1(); //無需知道具體接收者
invoker.setCommand(command);
invoker.action();
}
}