SSM：Spring + Spring MVC + MyBatis 的整合

SSM

前言

在完成 Spring 、Spring MVC 与 MyBatis 基础知识的学习后，下面简单介绍 SSM 框架的整合使用。

整合

SSM，是 Java 开发中常用的一个 Web 框架组合，用于构建基于 Spring 和 MyBatis 的 Web 应用（ Spring MVC 是 Spring 框架的扩展）。

简单示例：
首先，创建一个 Maven 工程（ Web 项目）后，在 pom.xml 中添加依赖

<dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version><scope>compile</scope></dependency><!-- https://mvnrepository.com/artifact/org.springframework/spring-context --><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.3.25</version></dependency><!-- https://mvnrepository.com/artifact/org.springframework/spring-web --><dependency><groupId>org.springframework</groupId><artifactId>spring-web</artifactId><version>5.3.25</version></dependency><!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc --><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.3.25</version></dependency><!-- https://mvnrepository.com/artifact/org.springframework/spring-tx --><dependency><groupId>org.springframework</groupId><artifactId>spring-tx</artifactId><version>5.3.25</version></dependency><!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects --><dependency><groupId>org.springframework</groupId><artifactId>spring-aspects</artifactId><version>5.3.25</version></dependency><!-- https://mvnrepository.com/artifact/org.springframework/spring-orm --><dependency><groupId>org.springframework</groupId><artifactId>spring-orm</artifactId><version>5.3.25</version></dependency><!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api --><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>3.1.0</version><scope>provided</scope></dependency><!-- https://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api --><dependency><groupId>javax.servlet.jsp</groupId><artifactId>javax.servlet.jsp-api</artifactId><version>2.3.3</version><scope>provided</scope></dependency><!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api --><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId><version>2.0.6</version></dependency><!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-nop --><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-nop</artifactId><version>2.0.6</version><type>jar</type></dependency><!-- https://mvnrepository.com/artifact/commons-logging/commons-logging --><dependency><groupId>commons-logging</groupId><artifactId>commons-logging</artifactId><version>1.2</version></dependency><!-- https://mvnrepository.com/artifact/org.apache.taglibs/taglibs-standard-impl --><dependency><groupId>org.apache.taglibs</groupId><artifactId>taglibs-standard-impl</artifactId><version>1.2.5</version></dependency><!-- https://mvnrepository.com/artifact/org.apache.taglibs/taglibs-standard-spec --><dependency><groupId>org.apache.taglibs</groupId><artifactId>taglibs-standard-spec</artifactId><version>1.2.5</version></dependency><!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.25</version></dependency><!-- https://mvnrepository.com/artifact/com.mchange/c3p0 --><dependency><groupId>com.mchange</groupId><artifactId>c3p0</artifactId><version>0.9.5.2</version></dependency><!-- https://mvnrepository.com/artifact/org.mybatis/mybatis --><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.6</version></dependency><!-- https://mvnrepository.com/artifact/org.mybatis.generator/mybatis-generator-core --><dependency><groupId>org.mybatis.generator</groupId><artifactId>mybatis-generator-core</artifactId><version>1.4.0</version></dependency><!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring --><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.0.6</version></dependency><!-- https://mvnrepository.com/artifact/org.mybatis.caches/mybatis-ehcache --><dependency><groupId>org.mybatis.caches</groupId><artifactId>mybatis-ehcache</artifactId><version>1.2.1</version></dependency><dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper</artifactId><version>5.3.2</version></dependency></dependencies><!--   UserMapper.xml 配置文件写在 src 找不到问题解决方案     --><build><resources><resource><!-- directory：指定资源文件的位置 --><directory>src/main/java</directory><includes><!-- “**”：表示任意级目录    “*”：表示任意任意文件 --><!-- mvn resources:resources ：对资源做出处理，先于 compile 阶段  --><include>**/*.properties</include><include>**/*.xml</include></includes><!--  filtering：开启过滤，用指定的参数替换 directory 下的文件中的参数(eg. ${name}) --><filtering>false</filtering></resource><resource><directory>src/main/resources</directory></resource></resources></build>

项目结构如图：

接着，在 webapp/WEB-INF 目录下的 web.xml 配置文件中，对 spring 和 springmvc 进行初始化配置

<?xml version="1.0" encoding="UTF-8"?><web-appxmlns="http://xmlns.jcp.org/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"version="4.0"><!-- 配置整个 web 应用的初始化参数，指定 spring 的配置文件所在位置 --><context-param><param-name>contextConfigLocation</param-name><param-value>classpath:spring.xml</param-value></context-param><!-- spring 与 javaweb 应用的整合 --><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener><!-- 配置前端控制器 dispatcherServlet --><servlet><servlet-name>dispatcherServlet</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><!-- 配置 springmvc 的配置文件所在位置 --><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:springmvc.xml</param-value></init-param><!-- 配置初始化参数，启动时创建 servlet 对象 --><load-on-startup>1</load-on-startup></servlet><!-- 配置url地址 --><servlet-mapping><servlet-name>dispatcherServlet</servlet-name><!-- 根目录下所有地址，其他 servlet 除外 --><url-pattern>/</url-pattern></servlet-mapping></web-app>

同时，在 resources 目录下创建 spring.xml 和 springmvc.xml 配置文件，并且进行相关配置

<?xml version="1.0" encoding="UTF-8"?><beansxmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:context="http://www.springframework.org/schema/context"xmlns:tx="http://www.springframework.org/schema/tx"xmlns:aop="http://www.springframework.org/schema/aop"xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring"xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring.xsd"><!-- spring.xml --><!-- 指定排除扫描 Controller 和 ControllerAdvice 包，避免与 springmvc 扫描重复 --><context:component-scanbase-package="cn.edu.ssmdemo"><context:exclude-filtertype="annotation"expression="org.springframework.stereotype.Controller"/><context:exclude-filtertype="annotation"expression="org.springframework.web.bind.annotation.ControllerAdvice"/></context:component-scan><!-- 在 Bean 的外部属性文件的使用中有所提及 --><!-- 使用context命名空间，通过 location 属性指定 properties 文件位置 --><context:property-placeholderlocation="classpath:jdbc.properties"/><beanid="dataSource"class="com.mchange.v2.c3p0.ComboPooledDataSource"><!-- 连接MySQL数据库的基本信息的配置 --><!-- 驱动程序类名：com.mysql.jdbc.Driver --><propertyname="driverClass"value="${jdbc.driverClass}"/><!-- JDBC URL：jdbc:mysql://<host>:<port>/<database_name> --><propertyname="jdbcUrl"value="${jdbc.url}"/><!-- 数据库用户名 --><propertyname="user"value="${jdbc.user}"/><!-- 数据库用户密码 --><propertyname="password"value="${jdbc.password}"/><!-- 若数据库中的连接数量不足时，向数据库申请的连接数量 --><propertyname="acquireIncrement"value="${acquireIncrement}"/><!-- 初始化数据库连接池时连接的数量 --><propertyname="initialPoolSize"value="${initialPoolSize}"/><!-- 数据库连接池最小的数据库连接数 --><propertyname="minPoolSize"value="${minPoolSize}"/><!-- 数据库连接池最大的数据库连接数 --><propertyname="maxPoolSize"value="${maxPoolSize}"/><!-- C3P0数据库连接池可以维护的Statement数量 --><propertyname="maxStatements"value="${maxStatements}"/><!-- 每个连接同时可以使用Statement的数量 --><propertyname="maxStatementsPerConnection"value="${maxStatementsPerConnection}"/></bean><!-- 配置事务管理器 --><beanid="dataSourceTransactionManager"class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><!-- 配置dataSource --><propertyname="dataSource"ref="dataSource"></property></bean><!-- 配置事务属性 --><tx:adviceid="txAdvice"transaction-manager="dataSourceTransactionManager"><tx:attributes><tx:methodname="get*"read-only="true"/><tx:methodname="load*"read-only="true"/><tx:methodname="find*"read-only="true"/><tx:methodname="select*"read-only="true"/><tx:methodname="*"read-only="false"/></tx:attributes></tx:advice><!-- 配置事务切入点 --><aop:config><aop:pointcutid="txPointcut"expression="execution(* cn.edu.ssmdemo.service.*.*(..))"/><aop:advisoradvice-ref="txAdvice"pointcut-ref="txPointcut"/></aop:config><!-- 配置 mybatis 整合 --><beanid="sessionFactory"class="org.mybatis.spring.SqlSessionFactoryBean"><propertyname="dataSource"ref="dataSource"/><propertyname="configLocation"value="classpath:mybatis.xml"/><propertyname="mapperLocations"value="classpath:cn/edu/ssmdemo/mapper/*.xml"/></bean><mybatis-spring:scanbase-package="cn.edu.ssmdemo.mapper"/></beans>

<?xml version="1.0" encoding="UTF-8"?><beansxmlns="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
       https://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/mvc
       https://www.springframework.org/schema/mvc/spring-mvc.xsd"><!-- springmvc.xml --><!-- 指定只扫描 Controller 和 ControllerAdvice 包 --><context:component-scanbase-package="cn.edu.ssmdemo"use-default-filters="false"><context:include-filtertype="annotation"expression="org.springframework.stereotype.Controller"/><context:include-filtertype="annotation"expression="org.springframework.web.bind.annotation.ControllerAdvice"/></context:component-scan><mvc:annotation-driven/><!-- 配置 springmvc 视图解析器 --><beanclass="org.springframework.web.servlet.view.InternalResourceViewResolver"><!-- 配置视图页面 --><propertyname="prefix"value="/WEB-INF/views/"></property><propertyname="suffix"value=".jsp"></property></bean><!-- 配置自动识别静态资源 --><mvc:default-servlet-handler/></beans>

另外，在 spring.xml 配置文件中，还要相应文件的创建与配置。在 resources 目录下再创建 jdbc.properties 资源文件和 mybatis.xml 配置文件，并且进行相关配置

jdbc.driverClass=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssmdemo?useSSL=false&serverTimezone=UTC
jdbc.user=root
jdbc.password=0123
acquireIncrement=5
initialPoolSize=10
minPoolSize=5
maxPoolSize=100
maxStatements=2
maxStatementsPerConnection=5

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPEconfigurationPUBLIC"-//mybatis.org//DTD Config 3.0//EN""https://mybatis.org/dtd/mybatis-3-config.dtd"><!-- mybatis.xml 配置文件 --><configuration><settings><!-- 懒加载配置 --><settingname="lazyLoadingEnabled"value="true"/><settingname="aggressiveLazyLoading"value="false"/><!-- 开启二级缓存 --><settingname="cacheEnabled"value="true"/></settings><!-- typeAliases：设置别名，简化类型名称的书写。用一个别名代替一个类全名 --><typeAliases><packagename="cn.edu.ssmdemo.model"/></typeAliases><!-- plugins 标签需要在 environments 标签前 --><plugins><plugininterceptor="com.github.pagehelper.PageInterceptor"></plugin></plugins></configuration>

然后，在 resources 目录下创建一个 Generator 的配置文件 mybatis_generator.xml ，并且进行相关配置

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPEgeneratorConfigurationPUBLIC"-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN""http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"><generatorConfiguration><contextid="DB2Tables"targetRuntime="MyBatis3"><commentGenerator><!-- 是否去除自动生成的注释 --><propertyname="suppressAllComments"value="true"/></commentGenerator><!-- MySQL数据库连接的信息：驱动类、连接地址、用户名、密码 --><jdbcConnectiondriverClass="com.mysql.cj.jdbc.Driver"connectionURL="jdbc:mysql://localhost:3306/ssmdemo?useUnicode=true&amp;characterEncoding=utf8&amp;useSSL=false&amp;serverTimezone=UTC"userId="root"password="0123"><propertyname="nullCatalogMeansCurrent"value="true"/></jdbcConnection><!-- Java 类型解析器，一般默认为 false --><javaTypeResolver><propertyname="forceBigDecimals"value="false"/></javaTypeResolver><!-- Domain 生成器：生成实体类。属性 targetProject ：生成 POJO 类的位置；其余默认 --><javaModelGeneratortargetPackage="cn.edu.ssmdemo.model"targetProject=".\src\main\java"/><!-- Mapping 生成器：生成映射文件。属性 targetProject ：mapper 映射文件生成的位置；其余默认 --><sqlMapGeneratortargetPackage="cn.edu.ssmdemo.mapper"targetProject=".\src\main\java"><!-- enableSubPackages :是否让 schema 作为包的后缀 --><propertyname="enableSubPackages"value="true"/></sqlMapGenerator><!-- Mapper 生成器：生成接口。targetProject 属性：mapper 接口生成的的位置 --><javaClientGeneratortype="XMLMAPPER"targetPackage="cn.edu.ssmdemo.mapper"targetProject=".\src\main\java"><!-- enableSubPackages :是否让 schema 作为包的后缀 --><propertyname="enableSubPackages"value="true"/></javaClientGenerator><!-- 指定数据表。tableName 属性：指定数据库的表名；domainObjectName 属性：生成对应实体类的名字；...Example 属性：设置关闭即可 --><tabletableName="user"domainObjectName="User"enableCountByExample="false"enableUpdateByExample="false"enableDeleteByExample="false"enableSelectByExample="false"selectByExampleQueryId="false"/></context></generatorConfiguration>

再在 MySQL 数据库 ssmdemo 中，创建数据表 user
表结构信息如图：

随之，在 test 目录下创建 RunSSMGenerator 类，通过数据库表结构自动生成对应的实体类、DAO 接口和 SQL 映射文件

packagecn.edu.ssmdemo.test;importorg.junit.Test;importorg.mybatis.generator.api.MyBatisGenerator;importorg.mybatis.generator.config.Configuration;importorg.mybatis.generator.config.xml.ConfigurationParser;importorg.mybatis.generator.exception.InvalidConfigurationException;importorg.mybatis.generator.exception.XMLParserException;importorg.mybatis.generator.internal.DefaultShellCallback;importjava.io.File;importjava.io.IOException;importjava.sql.SQLException;importjava.util.ArrayList;importjava.util.List;publicclassRunSSMGenerator{@TestpublicvoidmbgTest()throwsIOException,XMLParserException,InvalidConfigurationException,SQLException,InterruptedException{List<String> warnings =newArrayList<String>();boolean overwrite =true;// 只需修改 Generator 的配置文件名称即可String path =this.getClass().getClassLoader().getResource("mybatis_generator.xml").getPath();File configFile =newFile(path);ConfigurationParser cp =newConfigurationParser(warnings);Configuration config = cp.parseConfiguration(configFile);DefaultShellCallback callback =newDefaultShellCallback(overwrite);MyBatisGenerator myBatisGenerator =newMyBatisGenerator(config, callback, warnings);
        myBatisGenerator.generate(null);}}

运行生成实体类、DAO 接口和 SQL 映射文件后，接下来只实现 selectByPrimaryKey(Integer id) 方法作为简单的演示：
1.在 service 层创建接口 UserService

packagecn.edu.ssmdemo.service;importcn.edu.ssmdemo.model.User;//简单示例publicinterfaceUserService{UserselectByPrimaryKey(Integer id);}

2.在 service 层创建接口实现类 UserServiceImpl

packagecn.edu.ssmdemo.service;importcn.edu.ssmdemo.mapper.UserMapper;importcn.edu.ssmdemo.model.User;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Service;@Service("userService")publicclassUserServiceImplimplementsUserService{@AutowiredprivateUserMapper userMapper;@OverridepublicUserselectByPrimaryKey(Integer id){return userMapper.selectByPrimaryKey(id);}}

3.在 controller 层创建 UserController 类获取指定用户信息并放在视图上

packagecn.edu.ssmdemo.controller;importcn.edu.ssmdemo.model.User;importcn.edu.ssmdemo.service.UserService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Controller;importorg.springframework.ui.Model;importorg.springframework.web.bind.annotation.RequestMapping;@ControllerpublicclassUserController{@AutowiredprivateUserService userService;@RequestMapping("/user")publicStringuser(Model model){User user = userService.selectByPrimaryKey(20230903);
        model.addAttribute("user",user);System.out.println("用户信息："+ user);return"user";}}

4.在 webapp/WEB-INF/views 目录下创建对应的视图 user.jsp

<%--
  Created by IntelliJ IDEA.
  User: dell
  Date: 2023/9/3
  Time: 18:18
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html><body>
    用户信息：${user}
</body></html>

最后，启动 JRebel ，测试结果

结果如图：