JAVA设计模式（15）：行为型-命令模式（Command）

public interface Command{
	
	public void execute();
}
class ConcreteCommand implements Command{
	private Receiver receiver;

	public ConcreteCommand(Receiver receiver) {
		super();
		this.receiver = receiver;
	}

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

/**
 * 调用者、发起者
 */
public class Invoke {
	private Command command;

	public Invoke(Command command) {
		super();
		this.command = command;
	}
	/*业务方法，用于调用命令的方法*/
	public void call(){
		command.execute();
	}
}

public class Receiver {
	public void action(){
		System.out.println("action");
	}
}

public class Client {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Command command = new ConcreteCommand(new Receiver());
		Invoke Invoke = new Invoke(command);
		Invoke.call();
	}

}

• Struts2中，action的整个调用过程中就有命令模式。
• 数据库事务机制的底层实现
• 命令的撤销和恢复