java 反射机制 Demo 练习

 1 package controller;
 2 
 3 import java.io.IOException;
 4 import java.lang.reflect.Method;
 5 
 6 import javax.servlet.ServletException;
 7 import javax.servlet.http.HttpServlet;
 8 import javax.servlet.http.HttpServletRequest;
 9 import javax.servlet.http.HttpServletResponse;
10 
11 @SuppressWarnings("serial")
12 public abstract class DispatcherServlet extends HttpServlet {
13 
14     @Override
15     public void init() throws ServletException {
16     }
17 
18     @Override
19     public void doGet(HttpServletRequest request, HttpServletResponse response)
20             throws ServletException, IOException {
21         String requestURI = request.getRequestURI();
22         String methodName = requestURI.substring(requestURI.lastIndexOf("/") + 1);
23         String xpath = "/WEB-INF/view/errors.jsp";
24          // 根据指定的方法名称反射调用指定的方法
26         try {
27             Method method = this.getClass().getMethod(methodName,HttpServletRequest.class,HttpServletResponse.class);
28             // 反射调用方法
29             xpath = (String) method.invoke(this, request, response);
30         } catch (Exception e) {
31         }
32       request.getRequestDispatcher(xpath).forward(request, response);
33     }
34 
35     @Override
36     public void doPost(HttpServletRequest req, HttpServletResponse resp)
37             throws ServletException, IOException {
38         this.doGet(req, resp);
39     }
40 }

 1 package controller;
 2 
 3 import javax.servlet.annotation.WebServlet;
 4 import javax.servlet.http.HttpServletRequest;
 5 import javax.servlet.http.HttpServletResponse;
 6 
 7 @SuppressWarnings("serial")
 8 @WebServlet("/pages/*")
 9 public class ServiceServlet extends DispatcherServlet {
10     public String list(HttpServletRequest req, HttpServletResponse resp){
11         System.out.println("业务操作---------------");
12         return "/WEB-INF/view/list.jsp";
13     }
14 }