<dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-web</artifactId>            <version>4.3.2.RELEASE</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>           <artifactId>spring-webmvc</artifactId>            <version>4.3.2.RELEASE</version>        </dependency>

<dependency>            <groupId>javax.servlet</groupId>            <artifactId>javax.servlet-api</artifactId>            <version>3.1.0</version>        </dependency>        <dependency>            <groupId>javax.servlet.jsp</groupId>            <artifactId>jsp-api</artifactId>            <version>2.2</version>        </dependency>        <dependency>            <groupId>javax.servlet</groupId>            <artifactId>jstl</artifactId>            <version>1.2</version>        </dependency>

<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"    xsi:schemaLocation="http://www.springframework.org/schema/beans    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd    http://www.springframework.org/schema/tx    http://www.springframework.org/schema/tx/spring-tx-3.0.xsd    http://www.springframework.org/schema/aop    http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">    <context:component-scan base-package="com.ljd.controller"></context:component-scan>    <bean        class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <property name="prefix" value="/WEB-INF/jsp/" />        <property name="suffix" value=".jsp" />    </bean></beans>

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"    id="WebApp_ID" version="3.0">    <display-name>Archetype Created Web Application</display-name>    <context-param>        <param-name>contextConfigLocation</param-name>        <param-value>classpath:spring.xml,classpath:spring-mybatis.xml</param-value>    </context-param>    <filter>        <description>字符集过滤器</description>        <filter-name>encodingFilter</filter-name>        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>        <init-param>            <description>字符集编码</description>            <param-name>encoding</param-name>            <param-value>UTF-8</param-value>        </init-param>    </filter>    <filter-mapping>        <filter-name>encodingFilter</filter-name>        <url-pattern>/*</url-pattern>    </filter-mapping>    <listener>        <description>spring监听器</description>        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>    </listener>    <!-- 防止spring内存溢出监听器 -->    <listener>        <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>    </listener>    <!-- spring mvc servlet -->    <servlet>        <description>spring mvc servlet</description>        <servlet-name>springMvc</servlet-name>        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>        <init-param>            <description>spring mvc 配置文件</description>            <param-name>contextConfigLocation</param-name>            <param-value>classpath:spring-mvc.xml</param-value>        </init-param>        <load-on-startup>1</load-on-startup>    </servlet>    <servlet-mapping>        <servlet-name>springMvc</servlet-name>        <url-pattern>*.do</url-pattern>    </servlet-mapping>    <!-- 配置session超时时间，单位分钟 -->    <session-config>        <session-timeout>30</session-timeout>    </session-config>    <welcome-file-list>        <welcome-file>/html/login.html</welcome-file>        <welcome-file>/index.jsp</welcome-file>    </welcome-file-list></web-app>

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%><html><head><script type="text/javascript" src="/test/js/jquery.min.js"></script></head><body>    <h2>Hello World!</h2>    <form action="/test/userinfo.do" method="post" name="myForm" id="form">        输入用户名： <input type="text" name="username" id="username">        <button type="button" id="submit_btn">提交</button>    </form></body><script type="text/javascript">    $(‘#submit_btn‘).click(function() {        var username = $(‘#username‘).val();        if (username == ‘‘) {            alert(‘用户名不能为空‘);            return false        }        $(‘#form‘).submit();    });</script></html>

package com.ljd.controller;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpSession;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import com.ljd.pojo.User;import com.ljd.service.UserService;@Controllerpublic class UserController {    @Autowired    private UserService userService;    @RequestMapping("userinfo")    public String getUserInfo(@RequestParam String username, HttpSession session, HttpServletRequest request) {        System.out.println(username);        request.setAttribute("username", username);        User user = userService.getUserByUsername(username);        if (user == null) {            request.setAttribute("message", "用户不存在");        } else {            request.setAttribute("password", user.getPassword());            request.setAttribute("message", "用户存在");        }        return "userinfo";    }}

<%@ 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>    message:${message }    <br /> username:${username }    <br />password:${password }</body></html>