MVC案例之多个请求对应一个servlet

CustomerServlet

package com.aff.mvcapp.servlet;
import java.io.IOException;
import java.lang.reflect.Method;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/customerServlet")
public class CustomerServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 1. 获取ServletPath: /edit.do 或 addCustomer.do
        String servletPath = request.getServletPath();
        // 2.去除 / 和 .do 得到类似于 edit 或 addCustomer 这样的字符串
        String methodName = servletPath.substring(1);
        methodName = methodName.substring(0, methodName.length() - 3);

        try {
            // 3.利用反射获取 methodName 对应的方法
            Method method = getClass().getDeclaredMethod(methodName, HttpServletRequest.class,
                    HttpServletResponse.class);
            // 4.利用反射调用对应的方法
            method.invoke(this, request, response);
        } catch (Exception e) {
            //e.printStackTrace();
            //可以有一些响应
            response.sendRedirect("error.jsp");
        }
    }

    private void edit(HttpServletRequest request, HttpServletResponse response) {
        System.out.println("edit");
    }

    private void update(HttpServletRequest request, HttpServletResponse response) {
        System.out.println("update");
    }

    private void query(HttpServletRequest request, HttpServletResponse response) {
        System.out.println("query");
    }

    private void delete(HttpServletRequest request, HttpServletResponse response) {
        System.out.println("delete");
    }

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    version="3.1">
    <servlet>
        <servlet-name>CustomerServlet</servlet-name>
        <servlet-class>com.aff.mvcapp.servlet.CustomerServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>CustomerServlet</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>

</web-app>

test.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<a href="addCustomer.do">Add</a>
<br><br>
<a href="query.do">Query</a>
<br><br>
<a href="delete.do">Delete</a>
<br><br>
<a href="edit.do">Edit</a>
<br><br>
</body>
</html>

error.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<a href="addCustomer.do">Add</a>
<br><br>
<a href="query.do">Query</a>
<br><br>
<a href="delete.do">Delete</a>
<br><br>
<a href="edit.do">Edit</a>
<br><br>
</body>
</html>


 response.sendRedirect("error.jsp");

目录

All that work will definitely pay off