基于Maven的SSM框架搭建

Maven + Spring + Spring MVC + Mybatis + MySQL整合SSM框架

1.数据库准备

本文主要想实现SSM框架的搭建，并基于该框架实现简单的登录功能，那么先新建一张user_t表：

DROP TABLE IF EXISTS `user_t`;  

CREATE TABLE `user_t` (
  `id` INT(11) NOT NULL AUTO_INCREMENT,
  `user_name` VARCHAR(40) NOT NULL,
  `password` VARCHAR(255) NOT NULL,
  `age` INT(4) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;  

然后再插入一条数据：

INSERT  INTO `user_t`(`id`,`user_name`,`password`,`age`) VALUES (1,'测试','sfasgfaf',24);

为了简单起见，密码暂时先用明文，后面框架搭建成功后在改为MD5加密。

那么查看下user_login表的内容：

mysql> select * from user_t;
+----+-----------+----------+-----+
| id | user_name | password | age |
+----+-----------+----------+-----+
|  1 | 测试      | sfasgfaf |  24 |
+----+-----------+----------+-----+
1 row in set (0.00 sec)

2.Maven Web项目创建

新建一个Maven Project，然后输入Group Id和Artifact Id，点击Finish就完成了。

3.开始整合Spring Spring MVC Mybatis

用过Maven的都知道，有了Maven就没必要去网上下载一对jar文件然后自己去管理，直接在pom.xml中添加依赖就可以：

<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>20171117</groupId>
 <artifactId>SSM</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>SSM Maven Webapp</name>
  <url>http://maven.apache.org</url>

  <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.3.2.RELEASE</version>
      <relativePath></relativePath>
  </parent>

   <properties>
        <!-- spring版本号 -->
        <spring.version>4.0.2.RELEASE</spring.version>
        <!-- mybatis版本号 -->
        <mybatis.version>3.2.6</mybatis.version>
        <!-- log4j日志文件管理包版本 -->
        <slf4j.version>1.7.7</slf4j.version>
        <log4j.version>1.2.17</log4j.version>
    </properties>  

    <dependencies>
    <!-- https://mvnrepository.com/artifact/commons-logging/commons-logging -->
<dependency>
    <groupId>commons-logging</groupId>
    <artifactId>commons-logging</artifactId>
    <version>1.2</version>
</dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <!-- 表示开发的时候引入，发布的时候不会加载此包 -->
            <scope>test</scope>
        </dependency>
        <!-- spring核心包 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>  

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-oxm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>  

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>  

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>  

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>  

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- mybatis核心包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        <!-- mybatis/spring包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.2.2</version>
        </dependency>
        <!-- 导入java ee jar 包 -->
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>7.0</version>
        </dependency>
        <!-- 导入Mysql数据库链接jar包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.30</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>1.2.2</version>
        </dependency>
        <!-- JSTL标签类 -->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <!-- 日志文件管理包 -->
        <!-- log start -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>  

        <!-- 格式化对象，方便输出日志 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.1.41</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 -->
        <!-- 映入JSON -->
        <dependency>
            <groupId>org.codehaus.jackson</groupId>
            <artifactId>jackson-mapper-asl</artifactId>
            <version>1.9.13</version>
        </dependency>
        <!-- 上传组件包 -->
        <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>1.9</version>
        </dependency>
    </dependencies>
  <build>
    <finalName>Test</finalName>
  </build>
</project>

3.1Spring和Mybatis的整合

3.1.1创建数据库属性文件jdbc.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://10.0.20.252:3306/mybatis
username=root
password=Free-Wi11
initialSize=0
maxActive=20
maxIdle=20 
minIdle=1 
maxWait=60000

3.1.2创建spring-mybatis配置文件

这个文件就是用来完成spring和mybatis的整合的。这里面也没有多少行配置，主要就是自动扫描，自动注入，配置数据库，详细配置如下：

spring-mybatis.xml

<?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:p="http://www.springframework.org/schema/p"
    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-3.1.xsd
                        http://www.springframework.org/schema/context
                        http://www.springframework.org/schema/context/spring-context-3.1.xsd
                        http://www.springframework.org/schema/mvc
                        http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
    <!-- 自动扫描 -->
    <context:component-scan base-package="com.cn.hnust" />
    <!-- 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完美整合，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/cn/hnust/mapping/*.xml"></property>
    </bean>  

    <!-- DAO接口所在包名，Spring会自动查找其下的类 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.cn.hnust.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>  

</beans>

3.1.3日志的输出配置

为了方便调试，一般都会使用日志来输出信息，Log4j是Apache的一个开放源代码项目，通过使用Log4j，我们可以控制日志信息输送的目的地是控制台，文件，GUI组件，甚至是套接口服务器，NT的事件记录器，UNIX Syslog守护进程等；我们也可以控制每一条日志的输出格式；通过定义每一条日志信息的级别，我们能够更加细致的控制日志的生成过程。

Log4j的配置很简单，而且也是通用的，下面给出一个基本的配置，换到其他项目中也无需做多大的调整。

下面给出配置文件目录：

log4j.properties

log4j.rootLogger=INFO,Console,File
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.Target=System.out
log4j.appender.Console.layout = org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=[%c] - %m%n
log4j.appender.File = org.apache.log4j.RollingFileAppender
log4j.appender.File.File = logs/ssm.log
log4j.appender.File.MaxFileSize = 10MB
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

3.1.4JUnit测试

经过以上步骤，我们已经完成了Spring和Mybatis的整合，这样就可以编写一段测试代码来检验Spring和Mybatis是否整合成功了。

3.1.4.1创建实体类User

User.java

package com.cn.hnust.pojo;

public class User {
    private int id;
    private String user_name;
    private String password;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUser_name() {
        return user_name;
    }
    public void setUser_name(String user_name) {
        this.user_name = user_name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }

}

3.1.4.2创建Dao接口，UserDao

UserDao.java

package com.cn.hnust.dao;

import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;

import com.cn.hnust.pojo.User;
@Repository
public interface UserDao {
//    @Select("select * from user_t where id=#{userId}")
    public User selectByPrimaryKey(int userId);
}

3.1.4.3User类与数据库user_t表的映射文件UserMapper.xml

UserMapper.xml

<?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">
<mapper namespace="com.cn.hnust.dao.UserDao">

    <resultMap type="com.cn.hnust.pojo.User" id="UserResult">
        <result property="id" column="id"/>
        <result property="user_name" column="user_ame"/>
        <result property="password" column="password"/>
    </resultMap>

    <select id="selectByPrimaryKey" parameterType="Integer" resultMap="UserResult">
        select * from user_t where id=#{userId}
    </select>
</mapper>

3.1.4.4建立Service接口IUserService

IUserService.java

package com.cn.hnust.service;

import com.cn.hnust.pojo.User;

public interface IUserService {
 public User getUserById(int userId);
}

3.1.4.5建立IUserService接口的实现类UserServiceImpl

UserServiceImpl.java

package com.cn.hnust.service.impl;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;

import com.cn.hnust.dao.UserDao;
import com.cn.hnust.pojo.User;
import com.cn.hnust.service.IUserService;

@Service("userService")
public class UserServiceImpl implements IUserService {
    @Resource
    private UserDao userDao;

    public User getUserById(int userId) {
        // TODO Auto-generated method stub
        return this.userDao.selectByPrimaryKey(userId);
    }

}

3.1.4.6建立测试类

测试类在src/test/java中建立，如果使用了Spring那么就可以使用注解的方式来引入配置文件和类，然后将service接口对象注入，就可以进行测试了。

如果测试成功，表示Spring和Mybatis已经整合成功了。输出信息使用的是Log4j打印到控制台。

TestMyBatis.java

package org.zsl.testmybatis;  

import javax.annotation.Resource;  

import org.apache.log4j.Logger;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;  

import com.alibaba.fastjson.JSON;
import com.cn.hnust.pojo.User;
import com.cn.hnust.service.IUserService;  

@RunWith(SpringJUnit4ClassRunner.class)     //表示继承了SpringJUnit4ClassRunner类
@ContextConfiguration(locations = {"classpath:spring-mybatis.xml"})  

public class TestMyBatis {
    private static Logger logger = Logger.getLogger(TestMyBatis.class);
//  private ApplicationContext ac = null;
    @Resource
    private IUserService userService = null;  

//  @Before
//  public void before() {
//      ac = new ClassPathXmlApplicationContext("applicationContext.xml");
//      userService = (IUserService) ac.getBean("userService");
//  }  

    @Test
    public void test1() {
        User user = userService.getUserById(1);
        // System.out.println(user.getUserName());
        // logger.info("值："+user.getUserName());
//        System.out.println(user.getUser_name());
        logger.info(user.getId() + ".................." + user.getUser_name() + "........." + user.getPassword());
    }
}

Run As -> JUnit Test

运行结果:

至此，完成了Spring和Mybatis这两大框架的整合，下面将继续进行SpringMVC整合进项目中。

3.2整合Spring MVC

3.2.1配置spring-mvc.xml

配置里面的注释很详细，在此就补多少了，主要是自动扫描控制器，视图模式，注解的启动着三个。

spring-mvc.xml

<?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:p="http://www.springframework.org/schema/p"
    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-3.1.xsd
                        http://www.springframework.org/schema/context
                        http://www.springframework.org/schema/context/spring-context-3.1.xsd
                        http://www.springframework.org/schema/mvc
                        http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
    <!-- 自动扫描该包，使SpringMVC认为包下用了@controller注解的类是控制器 -->
    <context:component-scan base-package="com.cn.hnust.controller" />
    <!--避免IE执行AJAX时，返回JSON出现下载文件 -->
    <bean id="mappingJacksonHttpMessageConverter"
        class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8</value>
            </list>
        </property>
    </bean>
    <!-- 启动SpringMVC的注解功能，完成请求和注解POJO的映射 -->
    <bean
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="mappingJacksonHttpMessageConverter" /> <!-- JSON转换器 -->
            </list>
        </property>
    </bean>
    <!-- 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">
        <!-- 这里的配置我的理解是自动给后面action的方法return的字符串加上前缀和后缀，变成一个 可用的url地址 -->
        <property name="prefix" value="/WEB-INF/pages/" />
        <property name="suffix" value=".jsp" />
    </bean>  

    <!-- 配置文件上传，如果没有使用文件上传可以不用配置，当然如果不配，那么配置文件中也不必引入上传组件包 -->
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- 默认编码 -->
        <property name="defaultEncoding" value="utf-8" />
        <!-- 文件大小最大值 -->
        <property name="maxUploadSize" value="10485760000" />
        <!-- 内存中的最大值 -->
        <property name="maxInMemorySize" value="40960" />
    </bean>   

</beans>

3.2.2配置web.xml文件

这里面对spring-mybatis.xml的引入以及配置的spring-mvc的Servlet就是为了完成SSM整合，之前Spring和Mybatis整合不需要再此处进行任何配置。配置一样有详细的注释。

web.xml

<?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"
    version="3.0">
    <display-name>Archetype Created Web Application</display-name>
    <!-- Spring和mybatis的配置文件 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring-mybatis.xml</param-value>
    </context-param>
    <!-- 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 -->
    <listener>
        <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>
        <servlet-name>SpringMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
        <async-supported>true</async-supported>
    </servlet>
    <servlet-mapping>
        <servlet-name>SpringMVC</servlet-name>
        <!-- 此处可以可以配置成*.do，对应struts的后缀习惯 -->
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <welcome-file-list>
        <welcome-file>/index.jsp</welcome-file>
    </welcome-file-list>  

</web-app> 

3.3测试

至此已经完成了SSM三大框架的整合了，接下来测试一下。

3.3.1新建jsp页面

success.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!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=ISO-8859-1">
<title>Success</title>
</head>
<body>
    <p>login success</p>
</body>
</html>

fail.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!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=ISO-8859-1">
<title>fail</title>
</head>
<body>
    <p>login fail</p>
</body>
</html>

3.3.2建立UserController类

UserController.java 控制器

package com.cn.hnust.controller;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;

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

import com.cn.hnust.pojo.User;
import com.cn.hnust.service.IUserService;

@Controller
@RequestMapping("/user")
public class UserController {
   @Resource
   private IUserService userService;  

   @RequestMapping("/showUser")
   @ResponseBody
   public String toIndex(HttpServletRequest request,Model model){
       int userId = Integer.parseInt(request.getParameter("id"));
       User user = this.userService.getUserById(userId);
       model.addAttribute("user", user);
       System.out.println(user.getPassword());
       if ( user.getPassword().equals("12345") ) {
           return "success" + user.getPassword();
       } else {
           return "fail" + user.getPassword();
       }
//       return "success";
   }
} 

这个控制器写的比较简单，就是从浏览器访问/user/showUser?id=1，然后去数据库中取出id为1的用户的信息，判断该用户的密码和“12345”是否相同，如果相同则返回success字符串 + 该用户的密码，否则返回fail字符串 + 该用户的密码，由之前我们存到数据库中的id=1的用户的密码来看，其显然应该返回fail + 该用户的密码：

3.3.3部署项目

Run As -> Run On Server

在浏览器中输入http://localhost:8080/Test/user/showUser?id=1，运行的结果为：

至此，SSM三大框架的整合就完成了，在此基础上可以再太你家啊其他功能。

也可以对UserController进行修改：

package com.cn.hnust.controller;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;

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

import com.cn.hnust.pojo.User;
import com.cn.hnust.service.IUserService;

@Controller
@RequestMapping("/user")
public class UserController {
   @Resource
   private IUserService userService;  

   @RequestMapping("/showUser")
//   @ResponseBody
   public String toIndex(HttpServletRequest request,Model model){
       int userId = Integer.parseInt(request.getParameter("id"));
       User user = this.userService.getUserById(userId);
       model.addAttribute("user", user);
       System.out.println(user.getPassword());
       if ( user.getPassword().equals("12345") ) {
//           return "success" + user.getPassword();
           return "success";
       } else {
//           return "fail" + user.getPassword();
       }
//       return "success";
       return "fail";
   }
} 

验证id=1的用户的密码是否是“12345”，如果是则返回success.jsp页面，否则返回fail.jsp页面，注意去掉了@ResponseBody的注解，返回的就是页面

运行结果：