Spring 整合 MyBatis 教程（SSM 整合）

前言

本文主要介绍 Spring + Spring MVC + MyBatis 整合（SSM），开发工具基于 Eclipse + Maven。值得一提的是，下文只给出 SSM 整合所需的最小配置内容，在生产环境需要适当优化项目的配置，尤其是 Log4j2、Druid 的配置。完整的项目代码可以直接从 GitHub 下载对应章节 ssm-study。

版本说明

名称	版本
Spring	4.3.2.RELEASE
MyBatis	3.4.1
Druid	1.0.25
Log4j2	2.6.2
MySQL	5.7.26

官方整合案例

• MyBatis JPetStore

准备工作

数据库初始化

本文的案例代码依赖以下数据库表结构，因此需要提前初始化好数据库才能运行项目。

--- 创建数据库
CREATE DATABASE `mybatis_lesson` DEFAULT CHARACTER SET utf8mb4;

--- 创建数据库表
CREATE TABLE `t_employee` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `last_name` varchar(255) DEFAULT NULL,
  `gender` char(1) DEFAULT NULL,
  `email` varchar(255) DEFAULT NULL,
  `dept_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

--- 插入表数据
insert into t_employee(id, last_name, gender, email) values(1, 'Jim','1', 'jim@gmail.com');
insert into t_employee(id, last_name, gender, email) values(2, 'Tom','1', 'tom@gmail.com');
insert into t_employee(id, last_name, gender, email) values(3, 'Peter','1', 'peter@gmail.com');

创建 Maven Web 项目

在 Eclipse 内，提前创建好基于 Maven 的 Web 项目。由于篇幅有限，这里不再累述创建步骤，详细教程可看这里。

快速开始

引入 Maven 依赖

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>11</maven.compiler.target>
    <log4j.version>2.6.2</log4j.version>
    <mysql.version>5.1.37</mysql.version>
    <druid.version>1.0.25</druid.version>
    <mybatis.version>3.4.1</mybatis.version>
    <mybatis-spring.version>1.3.0</mybatis-spring.version>
    <servlet.version>3.1.0</servlet.version>
    <spring.version>4.3.2.RELEASE</spring.version>
    <gson.version>2.7</gson.version>
    <commons-collections.version>3.2.2</commons-collections.version>
</properties>

<dependencies>
    <!-- Junit -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.11</version>
        <scope>test</scope>
    </dependency>

    <!-- Servlet -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.0.1</version>
        <scope>provided</scope>
    </dependency>

    <!-- JSTL -->
    <dependency>
        <groupId>taglibs</groupId>
        <artifactId>standard</artifactId>
        <version>1.1.2</version>
    </dependency>

    <dependency>
        <groupId>jstl</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>

    <!-- Log4j2 -->
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>${log4j.version}</version>
    </dependency>

    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>${log4j.version}</version>
    </dependency>

    <!-- MySQL -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>${mysql.version}</version>
    </dependency>

    <!-- Druid -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>${druid.version}</version>
    </dependency>

    <!-- Mybatis -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>${mybatis.version}</version>
    </dependency>

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

    <!-- Spring IOC -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>${spring.version}</version>
    </dependency>

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

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

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

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

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

    <!-- Spring Web -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>${spring.version}</version>
    </dependency>

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

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

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

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

    <!-- Spring Test -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>${spring.version}</version>
    </dependency>

    <!-- Common Tools -->
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>${gson.version}</version>
    </dependency>

    <dependency>
        <groupId>commons-collections</groupId>
        <artifactId>commons-collections</artifactId>
        <version>${commons-collections.version}</version>
    </dependency>
</dependencies>

创建项目配置文件

Log4j2 配置文件

在 /src/main/resources 目录下创建 log4j2.xml 配置文件，其中的配置内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
	<Appenders>
		<Console name="Console" target="SYSTEM_OUT">
			<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
		</Console>
	</Appenders>
	<Loggers>
		<Root level="error">
			<AppenderRef ref="Console" />
		</Root>
	</Loggers>
</Configuration>

数据库配置文件

在 /src/main/resources 目录下创建 db.properties 配置文件，其中的配置内容如下：

jdbc.user=root
jdbc.password=123456
jdbc.url=jdbc:mysql://127.0.0.1:3306/mybatis_lesson?characterEncoding=utf8&autoReconnect=true&useSSL=false&useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC

jdbc.miniPoolSize=10
jdbc.maxPoolSize=30
jdbc.initialPoolSize=1
jdbc.maxWait=60000
jdbc.timeBetweenEvictionRunsMillis=60000
jdbc.minEvictableIdleTimeMillis=300000
jdbc.preferredTestQuery=select 1

MyBatis 配置文件

在 /src/main/resources 目录下创建 mybatis-config.xml 配置文件，用于存放 MyBatis 的全局核心配置信息，其中的配置内容如下：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
 PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

	<settings>
		<!-- 开启二级缓存 -->
		<setting name="cacheEnabled" value="true" />
		<!-- 开启驼峰命名自动映射 -->
		<setting name="mapUnderscoreToCamelCase" value="true" />
	</settings>

</configuration>

Spring 配置文件

Spring MVC 配置文件

在 /src/main/resources 目录下创建 application-servlet.xml 配置文件，用于配置 Spring MVC 的运行，其中的配置内容如下：

<?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/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
		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">

	<!-- Spring 扫描控制器组件 -->
	<context:component-scan base-package="com.clay.mybatis" use-default-filters="false">
		<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller" />
	</context:component-scan>

	<!-- Spring MVC 视图解析器 -->
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/pages/"></property>
		<property name="suffix" value=".jsp"></property>
	</bean>

	<!-- Spring MVC 注解驱动 -->
	<mvc:annotation-driven></mvc:annotation-driven>

	<mvc:default-servlet-handler />

</beans>

Spring Context 配置文件

在 /src/main/resources 目录下创建 application-context.xml 配置文件，Spring 整合 MyBatis 的核心配置信息就写在里面（也就是定义 SqlSessionFactoryBean 的 Bean），其中的配置内容如下：

<?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:mybatis-spring="http://mybatis.org/schema/mybatis-spring" xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

	<!-- 引入数据库配置文件 -->
	<context:property-placeholder location="classpath:db.properties" />

	<!-- 扫描组件 -->
	<context:component-scan base-package="com.clay.mybatis">
		<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />
	</context:component-scan>

	<!-- 数据源 -->
	<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
		<property name="url" value="${jdbc.url}" />
		<property name="username" value="${jdbc.user}" />
		<property name="password" value="${jdbc.password}" />
		<property name="maxActive" value="${jdbc.maxPoolSize}" />
		<property name="initialSize" value="${jdbc.initialPoolSize}" />
		<property name="maxWait" value="${jdbc.maxWait}" />
		<property name="minIdle" value="${jdbc.miniPoolSize}" />
		<property name="timeBetweenEvictionRunsMillis" value="${jdbc.timeBetweenEvictionRunsMillis}" />
		<property name="minEvictableIdleTimeMillis" value="${jdbc.minEvictableIdleTimeMillis}" />
		<property name="validationQuery" value="${jdbc.preferredTestQuery}" />
		<property name="testWhileIdle" value="true" />
		<property name="filters" value="stat" />
	</bean>

	<!-- 事务管理 -->
	<bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<property name="dataSource" ref="dataSource" />
	</bean>

	<!-- 开启基于注解的事务 -->
	<tx:annotation-driven transaction-manager="dataSourceTransactionManager" />

	<!-- 定义 SqlSessionFactory -->
	<bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
		<!-- 数据源 -->
		<property name="dataSource" ref="dataSource" />
		<!-- 类型别名 -->
		<property name="typeAliasesPackage" value="com.clay.mybatis.bean" />
		<!--指定 SQL 映射文件的位置 -->
		<property name="mapperLocations" value="classpath*:mapper/**/*.xml" />
		<!-- 指定 MyBatis 全局配置文件的位置 -->
		<property name="configLocation" value="classpath:mybatis-config.xml" />
	</bean>

	<!-- 定义 SqlSessionTemplate -->
	<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
		<constructor-arg name="sqlSessionFactory" ref="sqlSessionFactoryBean" />
	</bean>

	<!-- 扫描 MyBatis 的 Mapper 接口 -->
	<mybatis-spring:scan base-package="com.clay.mybatis.dao" />

	<!-- 或者使用以下的配置来扫描 Mapper 接口 -->
	<!--
	<bean id="configure" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
		<property name="basePackage" value="com.clay.mybatis.dao"></property>
	</bean>
	-->

</beans>

更改 web.xml 配置文件

更改 /src/main/webapp/WEB-INF 目录下的 web.xml 的配置文件，其中的配置内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://JAVA.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

	<!-- Spring 配置 -->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath:application-context.xml</param-value>
	</context-param>

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

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

	<servlet-mapping>
		<servlet-name>spring</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>

	<!-- 字符集编码过滤器 -->
	<filter>
		<filter-name>CharacterEncodingFilter</filter-name>
		<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
		<init-param>
			<param-name>encoding</param-name>
			<param-value>utf-8</param-value>
		</init-param>
		<init-param>
			<param-name>forceEncoding</param-name>
			<param-value>true</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>CharacterEncodingFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

</web-app>

项目核心代码

DAO 层

• EmployeeMapper

package com.clay.mybatis.dao;

import java.util.List;

import org.apache.ibatis.annotations.Mapper;

import com.clay.mybatis.bean.Employee;

@Mapper
public interface EmployeeMapper {

	public List<Employee> queryAll();

	public boolean delEmpById(Long id);

}

Service 层

• EmployeeService

package com.clay.mybatis.service;

import java.util.List;

import com.clay.mybatis.bean.Employee;

public interface EmployeeService {

	public List<Employee> list();

	public boolean deleteEmployee(Long id);

}

• EmployeeServiceImpl

package com.clay.mybatis.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.clay.mybatis.bean.Employee;
import com.clay.mybatis.dao.EmployeeMapper;
import com.clay.mybatis.service.EmployeeService;

@Service
public class EmployeeServiceImpl implements EmployeeService {

	@Autowired
	private EmployeeMapper employeeMapper;

	@Override
	public List<Employee> list() {
		return this.employeeMapper.queryAll();
	}

	@Override
	public boolean deleteEmployee(Long id) {
		return this.employeeMapper.delEmpById(id);
	}

}

Controller 层

• HomePageController

package com.clay.mybatis.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HomePageController {

	@RequestMapping("/")
	public String index() {
		return "index";
	}

	@RequestMapping("/index.jsp")
	public String indexJsp() {
		return "index";
	}

	@RequestMapping("/index.html")
	public String indexHtml() {
		return "index";
	}

}

• EmployeeController

package com.clay.mybatis.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;

import com.clay.mybatis.bean.Employee;
import com.clay.mybatis.service.EmployeeService;

@Controller
@RequestMapping("/employee")
public class EmployeeController {

	@Autowired
	private EmployeeService employeeService;

	@RequestMapping("/list")
	public ModelAndView list() {
		List<Employee> list = this.employeeService.list();
		ModelAndView view = new ModelAndView("/employee/list", "employees", list);
		return view;
	}

	@ResponseBody
	@RequestMapping("/delete/{id}")
	public boolean deleteEmployee(@PathVariable("id") Long id) {
		return this.employeeService.deleteEmployee(id);
	}

}

JSP 页面代码

提示

根据上面的 web.xml 配置文件，JSP 页面的源文件统一存放在 /src/main/webapp/WEB-INF/pages 目录下。

• 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>员工列表</title>
</head>
<body>
	<a href="/ssm-study/employee/list/">查询所有员工信息</a>
</body>
</html>

• /employee/list.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!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>员工列表</title>
</head>
<body>
	<table>
		<tr>
			<th>id</th>
			<th>lastName</th>
			<th>email</th>
			<th>gender</th>
		</tr>
		<c:forEach items="${requestScope.employees}" var="employee">
			<tr>
				<td>${employee.id }</td>
				<td>${employee.lastName }</td>
				<td>${employee.email }</td>
				<td>${employee.gender }</td>
			</tr>
		</c:forEach>
	</table>
</body>
</html>

SQL 映射文件

提示

根据上面的 application-context.xml 配置文件，SQL 映射文件统一存放在 /src/main/resources/mapper 目录下。

<?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">

<mapper namespace="com.clay.mybatis.dao.EmployeeMapper">

	<select id="queryAll" resultType="Employee">
		select id, last_name, gender, email
		from t_employee
	</select>

	<delete id="delEmpById" parameterType="Long">
		delete from t_employee
		where id = #{id}
	</delete>

</mapper>

项目代码测试

在 Eclipse 内将项目部署到 Tomcat 服务器，然后浏览器打开 http://127.0.0.1:8080/ssm-study/employee/list/，若看到下面的页面内容，则说明 Spring 成功整合了 MyBatis。

项目完整的目录结构图