我已经阅读了其他相关的帖子,但仍然不太清楚如何,或者是否可以在
Java中动态地(实现的接口).我的印象是我必须用反思去做.
我正在开展的具体项目需要使用许多支票实例,而且在我看来,这是一个不合时宜的事情,所以不妨感谢任何想法/解决方案.
下面是一个迷你的例子,我写的只是为了澄清我想要做什么.如果您需要更多信息,请告诉我们
接口:
public interface IRobot { String getName(); }
实现:
public class RoboCop implements IRobot { String name = this.getClass()+this.getClass().getName(); public RoboCop() {} public String getName() { return name; } } public class T1000 implements IRobot { String name = this.getClass()+this.getClass().getName(); public T1000() {} public String getName() { return name; } }
处理实现的类:
import java.util.LinkedList; import java.util.List; public class RobotFactory { public static void main(String[] args) { new RobotFactory(); } public RobotFactory() { List<IRobot> robots = new LinkedList<IRobot>(); robots.add( new RoboCop() ); robots.add( new T1000() ); System.out.println("Test 1 - Do not cast,and call deploy(robot)"); for(IRobot robot : robots) { deploy(robot); // deploy(Object robot) will be called for each.. } System.out.println("Test 2 - use instanceof"); for(IRobot robot : robots) { // use instanceof,works but can get messy if(robot instanceof RoboCop) { deploy((RoboCop)robot); } if(robot instanceof T1000) { deploy((T1000)robot); } } System.out.println("Test 3 - dynamically cast using reflection?"); for(IRobot robot : robots) { //deploy((<Dynamic cast based on robot's type>)robot); // <-- How to do this? } } public void deploy(RoboCop robot) { System.out.println("A RoboCop has been received... preparing for deployment."); // preparing for deployment } public void deploy(T1000 robot) { System.out.println("A T1000 has been received... preparing for deployment."); // preparing for deployment } public void deploy(Object robot) { System.out.println("An unknown robot has been received... Deactivating Robot"); // deactivate } }
输出:
[RoboCop@42e816,T1000@9304b1] Test 1 - Do not cast,and call deploy(robot) An unknown robot has been received... Deactivating Robot An unknown robot has been received... Deactivating Robot Test 2 - use instanceof A RoboCop has been received... preparing for deployment. A T1000 has been received... preparing for deployment. Test 3 - dynamically cast using reflection?
所以,总结一下我的问题,在这种情况下我怎么能完全避免使用instanceof.谢谢.