Command 设计模式

package Command;
/**定义命令的接口，声明执行的方法**/
public interface Command {
    public void execute();
}

package Command;
/**命令接口实现对象，通常会持有接受者，并调用接受者的功能来完成命令要执行的操作**/
public class ConcreteCommand implements Command {
    private Receiver receive = null;
    private String status;

    public ConcreteCommand(final Receiver receive) {
        this.receive = receive;
    }

    @Override
    public void execute() {
        // TODO Auto-generated method stub
        this.receive.action();
    }

}

package Command;
/**要求命令对象执行请求，通常会持有命令对象，可以持有很多的命令对象。这个是客户端真正触发命令并要求命令执行相应操作的地方，也就是说相当于使用命令对象的入口**/
public class Invoker {
    private Command command = null;

    public Command getCommand() {
        return command;
    }

    public void setCommand(final Command command) {
        this.command = command;
    }

    public void runCommand() {
        this.command.execute();
    }
}

package Command;
/**接收者，真正执行命令的对象。任何类都可能成为一个接收者,只要它能够实现命令要求的相应功能**/
public class Receiver {
    public void action() {
        System.out.println("Receive something, run action");
    }
}

package JTest;

import static org.junit.Assert.*;

import org.junit.Test;

import Command.Command;
import Command.ConcreteCommand;
import Command.Invoker;
import Command.Receiver;

public class CommandTest {

    @Test
    public void test() {
        // fail("Not yet implemented");
        final Receiver receiver = new Receiver();
        final Command command = new ConcreteCommand(receiver);
        final Invoker invoker = new Invoker();
        invoker.setCommand(command);
        invoker.runCommand();
    }

}