java 反射机制 Demo 练习

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.

package controller;

import java.io.IOException;
import java.lang.reflect.Method;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@SuppressWarnings("serial")
public abstract class DispatcherServlet extends HttpServlet {

    @Override
    public void init() throws ServletException {
    }

    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String requestURI = request.getRequestURI();
        String methodName = requestURI.substring(requestURI.lastIndexOf("/") + 1);
        String xpath = "/WEB-INF/view/errors.jsp";
         // 根据指定的方法名称反射调用指定的方法
        try {
            Method method = this.getClass().getMethod(methodName,HttpServletRequest.class,HttpServletResponse.class);
            // 反射调用方法
            xpath = (String) method.invoke(this, request, response);
        } catch (Exception e) {
        }
      request.getRequestDispatcher(xpath).forward(request, response);
    }

    @Override
    public void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        this.doGet(req, resp);
    }
}

2. 定义一个ServiceServlet 继承 DispatcherServlet

package controller;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@SuppressWarnings("serial")
@WebServlet("/pages/*")
public class ServiceServlet extends DispatcherServlet {
    public String list(HttpServletRequest req, HttpServletResponse resp){
        System.out.println("业务操作---------------");
        return "/WEB-INF/view/list.jsp";
    }
}

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