用Maven整合SSM项目实例

             本人在学习Maven之余，为了深入了解Maven的用法，决定创建一个SSM整合实例。项目是自己实际搭建，真实可用。

1. 技术介绍

             SSM（Spring+SpringMVC+Mybatis）

                  Spring是一种轻量级框架，这是众所周知的，开发者只需要把一些常用的如日志，事务管理在配置文件中申明，能大大降低代码的耦合，减少代码侵入。他的核心是                      IOC（控制反转）和AOP（面向切面编程），具体大家想了解深入可以上网查阅，这里不再多讲。

                  SpringMVC顾名思义就是运用Spring框架使用MVC思想实现，他的核心就是前端控制器（DispatcherServlet），它的工作原理是：

                   1、客户端发出一个http请求给web服务器，web服务器对http请求进行解析，如果匹配DispatcherServlet的请求映射路径（在web.xml中指定），web容器将请求转交给

              DispatcherServlet.

                   2、DipatcherServlet接收到这个请求之后将根据请求的信息（包括URL、Http方法、请求报文头和请求参数Cookie等）以及HandlerMapping的配置找到处理请求的处理                器（Handler）。

                   3-4、DispatcherServlet根据HandlerMapping找到对应的Handler,将处理权交给Handler（Handler将具体的处理进行封装），再由具体的HandlerAdapter对Handler进行                具体的调用。

                   5、Handler对数据处理完成以后将返回一个ModelAndView()对象给DispatcherServlet。

                   6、Handler返回的ModelAndView()只是一个逻辑视图并不是一个正式的视图，DispatcherSevlet通过ViewResolver将逻辑视图转化为真正的视图View。

                   7、Dispatcher通过model解析出ModelAndView()中的参数进行解析最终展现出完整的view并返回给客户端。

                    Mybatis是支持定制化 SQL、存储过程以及高级映射的优秀的持久层框架。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。MyBatis 可以对                      配置和原生Map使用简单的 XML 或注解，将接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java对象)映射成数据库中的记录。

1. 数据库创建

              这里是MySQL数据库，数据库表创建如下图：

              

CREATE TABLE tb_user(
    id int(11) NOT NULL AUTO_INCREMENT,
    user_name varchar(40) NOT NULL,
    password varchar(40) NOT NULL,
    age int(4) NOT NULL,
    PRIMARY KEY(id))
     ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

1. SSM整合步骤

               完整项目整合如下图所示：

                            

             1.创建Maven的Web项目（这个在上一篇文章已经讲解了，这里就不再多讲）

             2.配置pom.xml,代码如下：

               

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>cn.temp</groupId>
  <artifactId>maven-web-demo02</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>maven-web-demo02 Maven Webapp</name>
  <url>http://maven.apache.org</url>
   <properties>    
        <srping.version>4.0.2.RELEASE</srping.version>    
        <mybatis.version>3.2.8</mybatis.version>    
        <slf4j.version>1.7.12</slf4j.version>    
        <log4j.version>1.2.17</log4j.version>    
    </properties>    
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
        <scope>provided</scope>
    </dependency>
    
     <!-- java ee包 -->    
        <dependency>    
            <groupId>javax</groupId>    
            <artifactId>javaee-api</artifactId>    
            <version>7.0</version> 
            <scope>provided</scope>   
        </dependency>    
        <!-- spring框架包 start -->    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-test</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-core</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-oxm</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-tx</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-jdbc</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-aop</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-context</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-context-support</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-expression</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-orm</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-web</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.springframework</groupId>    
            <artifactId>spring-webmvc</artifactId>    
            <version>${srping.version}</version>    
        </dependency>    
        <!-- spring框架包 end -->    
        <!-- mybatis框架包 start -->    
        <dependency>    
            <groupId>org.mybatis</groupId>    
            <artifactId>mybatis</artifactId>    
            <version>${mybatis.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.mybatis</groupId>    
            <artifactId>mybatis-spring</artifactId>    
            <version>1.2.2</version>    
        </dependency>    
        <!-- mybatis框架包 end -->    
        <!-- 数据库驱动 -->    
        <dependency>    
            <groupId>mysql</groupId>    
            <artifactId>mysql-connector-java</artifactId>    
            <version>5.1.35</version>    
        </dependency>    
        <!-- 导入dbcp的jar包，用来在applicationContext.xml中配置数据库 -->    
        <dependency>    
            <groupId>commons-dbcp</groupId>    
            <artifactId>commons-dbcp</artifactId>    
            <version>1.4</version>    
        </dependency>    
        <!-- jstl标签类 -->    
        <dependency>    
            <groupId>jstl</groupId>    
            <artifactId>jstl</artifactId>    
            <version>1.2</version>    
        </dependency>    
        <!-- log start -->    
        <dependency>    
            <groupId>log4j</groupId>    
            <artifactId>log4j</artifactId>    
            <version>${log4j.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.slf4j</groupId>    
            <artifactId>slf4j-api</artifactId>    
            <version>${slf4j.version}</version>    
        </dependency>    
        <dependency>    
            <groupId>org.slf4j</groupId>    
            <artifactId>slf4j-log4j12</artifactId>    
            <version>${slf4j.version}</version>    
        </dependency>    
        <!-- log END -->    
        <!-- Json  -->    
        <!-- 格式化对象，方便输出日志 -->    
        <dependency>    
            <groupId>com.alibaba</groupId>    
            <artifactId>fastjson</artifactId>    
            <version>1.2.6</version>    
        </dependency>    
        <dependency>    
            <groupId>org.codehaus.jackson</groupId>    
            <artifactId>jackson-mapper-asl</artifactId>    
            <version>1.9.13</version>    
        </dependency>    
        <!-- 上传组件包 start -->    
        <dependency>    
            <groupId>commons-fileupload</groupId>    
            <artifactId>commons-fileupload</artifactId>    
            <version>1.3.1</version>    
        </dependency>    
        <dependency>    
            <groupId>commons-io</groupId>    
            <artifactId>commons-io</artifactId>    
            <version>2.4</version>    
        </dependency>    
        <dependency>    
            <groupId>commons-codec</groupId>    
            <artifactId>commons-codec</artifactId>    
            <version>1.10</version>    
        </dependency>    
        <!-- 上传组件包 end -->    
  </dependencies>
  <build>
    <finalName>maven-web-demo02</finalName>
  </build>
</project>

3.创建jdbc.properties文件

    

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/orcl
username=root
password=123qweasd

initialSize=0 
maxActive=20 
maxIdle=20
minIdle=1
maxWait=60000

4.创建日志属性文件

#u5B9Au4E49LOGu8F93u51FAu7EA7u522B 
log4j.rootLogger=INFO,Console,File 
#u5B9Au4E49u65E5u5FD7u8F93u51FAu76EEu7684u5730u4E3Au63A7u5236u53F0  
log4j.appender.Console=org.apache.log4j.ConsoleAppender 
log4j.appender.Console.Target=System.out
#u53EFu4EE5u7075u6D3Bu5730u6307u5B9Au65E5u5FD7u8F93u51FAu683Cu5F0FuFF0Cu4E0Bu9762u4E00u884Cu662Fu6307u5B9Au5177u4F53u7684u683Cu5F0F  
log4j.appender.Console.layout = org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=[%c] - %m%n

#u6587u4EF6u5927u5C0Fu5230u8FBEu6307u5B9Au5C3Au5BF8u7684u65F6u5019u4EA7u751Fu4E00u4E2Au65B0u7684u6587u4EF6
log4j.appender.File = org.apache.log4j.RollingFileAppender
#u6307u5B9Au8F93u51FAu76EEu5F55
log4j.appender.File.File = logs/ssm.log
#u5B9Au4E49u6587u4EF6u6700u5927u5927u5C0F
log4j.appender.File.MaxFileSize = 10MB
# u8F93u51FAu6240u4EE5u65E5u5FD7uFF0Cu5982u679Cu6362u6210DEBUGu8868u793Au8F93u51FADEBUGu4EE5u4E0Au7EA7u522Bu65E5u5FD7
log4j.appender.File.Threshold = ALL
log4j.appender.File.layout = org.apache.log4j.PatternLayout
log4j.appender.File.layout.ConversionPattern =[%p] [%d{yyyy-MM-dd HH:mm:ss}][%c]%m%n

5.接下来创建Spring和MyBatis整合文件

<?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:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

    <!-- 自动扫描 -->  
    <context:component-scan base-package="com.sgcc.user" >
    <!-- 不扫描@Controller注解的类-->
    <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
    
    <!-- 引入配置文件 -->  
    <bean id="propertyConfigurer"  
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">  
        <property name="location" value="classpath:jdbc.properties" />  
    </bean>  

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"  
        destroy-method="close">  
        <property name="driverClassName" value="${driver}" />  
        <property name="url" value="${url}" />  
        <property name="username" value="${username}" />  
        <property name="password" value="${password}" />  
        <!-- 初始化连接大小 -->  
        <property name="initialSize" value="${initialSize}"></property>  
        <!-- 连接池最大数量 -->  
        <property name="maxActive" value="${maxActive}"></property>  
        <!-- 连接池最大空闲 -->  
        <property name="maxIdle" value="${maxIdle}"></property>  
        <!-- 连接池最小空闲 -->  
        <property name="minIdle" value="${minIdle}"></property>  
        <!-- 获取连接最大等待时间 -->  
        <property name="maxWait" value="${maxWait}"></property>  
    </bean>  
    
    <!-- spring和MyBatis整合，不需要mybatis的配置映射文件 -->  
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  
        <property name="dataSource" ref="dataSource" />  
        <!-- 自动扫描mapping.xml文件 -->  
        <property name="mapperLocations" value="classpath:com/sgcc/user/mapping/*.xml"></property>  
    </bean>  
    
    <!-- DAO接口所在包名，Spring会自动查找其下的类 动态代理实现 不用写dao的实现类-->  
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">  
        <property name="basePackage" value="com.sgcc.user.dao" />  
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>  
    </bean>  
    
    <!-- (事务管理)transaction manager, use JtaTransactionManager for global tx -->  
    <bean id="transactionManager"  
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">  
        <property name="dataSource" ref="dataSource" />  
    </bean>  

    <tx:annotation-driven transaction-manager="transactionManager"/>
</beans>

6.创建SpringMVC文件，如下代码

<?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:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">

    <!-- 自动扫描该包 @controller注解的类-->  
    <context:component-scan base-package="com.sgcc.user.controller"/>  

      <!-- 静态资源处理 -->
    <mvc:default-servlet-handler/>

    <!--自动注册 RequestMappingHandlerMapping、RequestMappingHandlerAdapter 等bean -->
    <mvc:annotation-driven></mvc:annotation-driven>

    <!-- 定义跳转的文件的前后缀 ，视图模式配置-->  
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
        <property name="prefix" value="/WEB-INF/views/" />  
        <property name="suffix" value=".jsp" />  
    </bean>     
</beans>

7.接下来就是各个业务文件了，如下图所示：

8.创建UserController文件，如下图所示：

package com.sgcc.user.controller;
import javax.annotation.Resource;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

import com.sgcc.user.pojo.User;
import com.sgcc.user.service.UserService;
@Controller
public class UserController {
    /**
     * 使用@Autowired也可以，@Autowired默认按类型装配
     * @Resource 默认按名称装配，当找不到与名称匹配的bean才会按类型装配。
     */
    @Resource 
    private UserService userService;
    /**
     * 测试查询
     * 
     * @param id
     * @param model
     * @return
     */
    @RequestMapping("/showUser")
    public String testtoshowUser(@RequestParam(value = "id") Integer id, Model model) {
        System.out.println("id:" + id);
        User user = userService.getUserById(id);
        model.addAttribute("user", user);
        return "showUser";
    }

    /**
     * 测试添加数据
     * 
     * @param id
     * @param model
     * @return
     */
    @RequestMapping("/insertUser")
    public String testinsertUser() {
        User user = new User();
        user.setUserName("李清照");
        user.setPassword("3232322");
        user.setAge(22);
        int count = userService.insert(user);
        System.out.println("插入" + count + "条数据成功");
        return "showUser";
    }
}

9.创建UserDao

package com.sgcc.user.dao;

import com.sgcc.user.pojo.User;

public interface  UserDao {
    int deleteByPrimaryKey(Integer id);

    int insert(User record);

    int insertSelective(User record);

    User selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);
}

10.创建UserMapper.xml文件，代码如下

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<!-- namespace的值就是dao接口的完整路径，就这个demo而言namespace 就是userDao.java的完整路径-->
<mapper namespace="com.sgcc.user.dao.UserDao">
    <resultMap id="BaseResultMap" type="com.sgcc.user.pojo.User">
        <id column="id" property="id" jdbcType="INTEGER" />
        <result column="user_name" property="userName" jdbcType="VARCHAR" />
        <result column="password" property="password" jdbcType="VARCHAR" />
        <result column="age" property="age" jdbcType="INTEGER" />
    </resultMap>
    <sql id="Base_Column_List">
        id, user_name, password, age
    </sql>
    <select id="selectByPrimaryKey" resultMap="BaseResultMap"
        parameterType="java.lang.Integer">
        select
        <include refid="Base_Column_List" />
        from tb_user
        where id = #{id,jdbcType=INTEGER}
    </select>

    <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">
        delete from
        tb_user
        where id = #{id,jdbcType=INTEGER}
    </delete>

    <insert id="insert" parameterType="com.sgcc.user.pojo.User">
        insert into tb_user (id,
        user_name, password,
        age)
        values (#{id,jdbcType=INTEGER},
        #{userName,jdbcType=VARCHAR},
        #{password,jdbcType=VARCHAR},
        #{age,jdbcType=INTEGER})
    </insert>

    <insert id="insertSelective" parameterType="com.sgcc.user.pojo.User">
        insert into tb_user
        <trim prefix="(" suffix=")" suffixOverrides=",">
            <if test="id != null">
                id,
            </if>
            <if test="userName != null">
                user_name,
            </if>
            <if test="password != null">
                password,
            </if>
            <if test="age != null">
                age,
            </if>
        </trim>
        <trim prefix="values (" suffix=")" suffixOverrides=",">
            <if test="id != null">
                #{id,jdbcType=INTEGER},
            </if>
            <if test="userName != null">
                #{userName,jdbcType=VARCHAR},
            </if>
            <if test="password != null">
                #{password,jdbcType=VARCHAR},
            </if>
            <if test="age != null">
                #{age,jdbcType=INTEGER},
            </if>
        </trim>
    </insert>

    <update id="updateByPrimaryKeySelective" parameterType="com.sgcc.user.pojo.User">
        update tb_user
        <set>
            <if test="userName != null">
                user_name = #{userName,jdbcType=VARCHAR},
            </if>
            <if test="password != null">
                password = #{password,jdbcType=VARCHAR},
            </if>
            <if test="age != null">
                age = #{age,jdbcType=INTEGER},
            </if>
        </set>
        where id = #{id,jdbcType=INTEGER}
    </update>

    <update id="updateByPrimaryKey" parameterType="com.sgcc.user.pojo.User">
        update tb_user
        set
        user_name = #{userName,jdbcType=VARCHAR},
        password =
        #{password,jdbcType=VARCHAR},
        age = #{age,jdbcType=INTEGER}
        where id =
        #{id,jdbcType=INTEGER}
    </update>
</mapper>

12.创建User类

package com.sgcc.user.pojo;

public class User {
    private Integer id;

    private String userName;

    private String password;

    private Integer age;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName == null ? null : userName.trim();
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password == null ? null : password.trim();
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "User [id=" + id + ", userName=" + userName + ", password=" + password + ", age=" + age + "]";
    }    
}

13.创建UserService接口

package com.sgcc.user.service;

import com.sgcc.user.pojo.User;

public interface UserService {
    //根据id查找
    public User getUserById(Integer userid);

    //添加一条数据
    public int insert(User user);
}

14.创建UserServiceImpl实现类

package com.sgcc.user.service;
import javax.annotation.Resource;

import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.sgcc.user.dao.UserDao;
import com.sgcc.user.pojo.User;
@Transactional
@Service("userService")
public class UserServiceImpl implements UserService {

    /**
     * 因为没有在spring的文件中显式的声明userService实现类，直接通过getBean得到 userService 会找不到
     *  需要显式配置 @Service ("userService")，指定bean的名称
     *  相当与<bean id="userService" class="com.jxust.ssm.service.impl.UserServiceImpl"></bean>
     */
    @Resource
    private UserDao userDao;

    public User getUserById(Integer userid) {   
        return this.userDao.selectByPrimaryKey(userid);
    }

    @Override
    public int insert(User user) {
        return this.userDao.insert(user);
    }

}

16.配置程序入口web.xml文件

<?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" 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>maven-web-demo02</display-name>
  <!-- 编码过滤器 -->
    <filter>
        <filter-name>encodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <async-supported>true</async-supported>
        <init-param>
            <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>

    <!-- Spring监听器 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring-mybatis.xml</param-value>
    </context-param>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!--Spring MVC 配置servlet -->
    <servlet>
        <servlet-name>springDispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>springDispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

18.创建前端页面，index.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="showUser?id=2">ShowUser page</a><br>
    <a href="insertUser">insertUser </a>
</body>
</html>

19.创建showUser.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>测试</title>
</head>
<body>
    id:${user.id} <br>
    userName: ${user.userName} <br>
    password: ${user.password} <br>
    age: ${user.age} <br>
</body>
</html>

20启动服务，如下图所示：