最近在研究java 反射机制,看网上视频,并抄了下来研究,用到Servlet 注解,绝不亚于SpringMVC 的注解使用,特此记录分享,Servlet 再也不用为传递参数而判断担忧了,专注业务!
1. 首先定义一个父类,所有的业务操作全部继承之.
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 @Override15 public void init() throws ServletException {16 }17 18 @Override19 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 @Override36 public void doPost(HttpServletRequest req, HttpServletResponse resp)37 throws ServletException, IOException {38 this.doGet(req, resp);39 }40 }
2. 定义一个ServiceServlet 继承 DispatcherServlet
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 }
3. JSP页面自定义
4. 访问路径: http://localhost:8080/ReflectServlet/pages/list
5. 其他页面可拓展添加
原标题:java 反射机制 Demo 练习
关键词:JAVA