命令模式--command模式

首先来一个命令的接口：

package mode.command;

/**
 * 
 * 定义一个命令接口，其中有一个抽象的执行方法，参数人命令接收器
 * 
 * */
public interface Command {
	public void execute(CommandReceiver commandReceiver);
}

定义一个命令接受者的接口：

package mode.command;

/**
 * 
 * 命令接收类，包涵要执行的各种动作
 * 
 * 
 * */
public interface CommandReceiver {

	public void doSometingA();

	public void doSomethingB();
}

两个Command接口的实现类：

package mode.command;

public class CommandA implements Command {

	@Override
	public void execute(CommandReceiver commandReceiver) {
		commandReceiver.doSometingA();
	}

}

package mode.command;

public class CommandB implements Command {

	@Override
	public void execute(CommandReceiver commandReceiver) {
		commandReceiver.doSomethingB();
	}

}

定义一个命令接收者的实现类，这里使用单例模式来设计这个类

package mode.command;

public class CommandReceiverImplSingliton implements CommandReceiver {

	private static CommandReceiverImplSingliton commandReceiverImplSingliton;

	public static CommandReceiverImplSingliton getCommandSingliton() {
		if (null == commandReceiverImplSingliton) {
			commandReceiverImplSingliton = new CommandReceiverImplSingliton();
			return commandReceiverImplSingliton;
		} else {
			return commandReceiverImplSingliton;
		}
	}

	@Override
	public void doSometingA() {
		System.out.println("dodoododododododoodoAAAAA");

	}

	@Override
	public void doSomethingB() {
		System.out.println("dododoodododoodododoBBBBB");
	}
}

创建命令执行器：

package mode.command;

public class CommandExecutor {

	public void execute(Command command) {
		command.execute(CommandReceiverImplSingliton.getCommandSingliton());
	}
}

用client类来测试：

package mode.command;

public class Client {
	public static void main(String[] args) {
		Command commandA = new CommandA();
		Command commandB = new CommandB();
		
		CommandExecutor executor = new CommandExecutor();
		
		executor.execute(commandA);
		executor.execute(commandB);  
	}
}