Java-马士兵设计模式学习笔记-命令模式

1 public class Client {
2     
3     public void request(Server server){
4         server.addCommand(new TextCommand());
5         server.addCommand(new ImageCommand());
6         server.doSomething();
7     }
8 }

 1 public class Server {
 2 
 3     private List<Command> commands = new ArrayList<Command>();
 4 
 5     public void doSomething() {
 6         for(Command c : commands){
 7             c.execute();
 8         }
 9     }
10 
11     public void addCommand(Command command) {
12         commands.add(command);
13     }
14 
15 }

1 public abstract class Command {
2     
3     public abstract void execute();
4     public abstract void unDo();
5 
6 }

 1 public class TextCommand extends Command {
 2 
 3     @Override
 4     public void execute() {
 5         System.out.println("TextCommand...........");
 6     }
 7 
 8     @Override
 9     public void unDo() {
10         // 涉及到操作的历史记录
11     }
12 
13 }

 1 public class ImageCommand extends Command {
 2 
 3     @Override
 4     public void execute() {
 5         System.out.println("ImageCommand...........");
 6     }
 7 
 8     @Override
 9     public void unDo() {
10         // 涉及到操作的历史记录
11     }
12 
13 }

1 public class Test {
2     
3     @org.junit.Test
4     public void test(){
5         Client c = new Client();
6         c.request(new Server());
7     }
8 
9 }