Mybatis-14 整合 Spring 框架

1 目录结构

2 导入依赖

<!-- 添加Spring支持 -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-beans</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-tx</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aop</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aspects</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<!-- Mybatis -->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.6</version>
</dependency>
<!-- Mybatis-Spring -->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.3</version>
</dependency>
<!-- Mysql驱动 -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.21</version>
</dependency>
<!-- Druid数据库连接池 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.2.1</version>
</dependency>
<!-- 日志处理 -->
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
</dependency>
<!-- 单元测试 -->
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
</dependency>

3 实体类 & Mapper 接口 & SQL 映射文件

User 类
UserMapper 类
UserMapper.xml 文件

4 数据库连接配置和日志配置

db.properties & log4j.properties

5 Mybatis 全局配置文件

mybatis-config.xml

这里几乎没什么可配置的，<mappers> & <environments> 标签等都整合到 Spring 的配置文件中去了。

<?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>
        <!--开启日志-->
        <setting name="logImpl" value="STDOUT_LOGGING" />
    </settings>
</configuration>

6 Spring 全局配置文件

applicationContext.xml

在与 Spring 整合之前，我们都是在 Mybatis 的全局配置文件中管理数据源，并且 sqlSessionFactory 也是我们自己通过代码来完成注入的，但是现在与 Spring 整合了，这些操作都要交给 Spring 来管理了，所以下面我们来看一下 applicationContext.xml 文件中的配置：

<?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"
       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">
 
    <!-- 加载classpath下的db.properties文件 -->
    <context:property-placeholder location="classpath:db.properties"/>
 
    <!-- 配置数据源 -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${database.driver}" />
        <property name="url" value="${database.url}" />
        <property name="username" value="${database.username}" />
        <property name="password" value="${database.password}" />
    </bean>
 
    <!-- 配置sqlSessionFactory，SqlSessionFactoryBean是用来产生sqlSessionFactory的 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 加载上面配置好数据源 -->
        <property name="dataSource" ref="dataSource" />
        <!-- 加载mybatis的映射配置文件;XxxMapper.xml -->
        <property name="mapperLocations" value="classpath:com/thr/mapper/*.xml" />
        <!-- 加载mybatis的全局配置文件;mybatis-config.xml-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <!-- 配置别名，使用包扫描,扫描com.thr.pojo包下的所有实体 -->
        <property name="typeAliasesPackage" value="com.thr.pojo"/>
    </bean>
 
    <!-- 创建UserMapper接口的代理对象,这里是创建单个代理对象，不推荐这种方式，如果多个类就麻烦了
    这里的org.mybatis.spring.mapper.MapperFactoryBean<T>类就是用来创建 Mapper代理对象的类 -->
    <!--
    <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="mapperInterface" value="com.thr.mapper.UserMapper"/>
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>
    -->
 
    <!-- 加载所在包名下的Mapper接口，并且为其创建代理对象，推荐 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.thr.mapper" />
        <!-- 可选，如果不写，Spring启动时候。容器中自动会按照类型去把SqlSessionFactory对象注入进来 -->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
    </bean>
</beans>

7 测试代码

public class UserMapperTest {
    //创建ApplicationContext容器
    private ApplicationContext applicationContext = null;
 
    @Before
    public void getApplicationContext() throws Exception {
        //获取Spring容器
        applicationContext = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
    }
    //查询所有用户
    @Test
    public void testSelectAllUser(){
        //获取UserMapper对象
        UserMapper userMapper = applicationContext.getBean("userMapper", UserMapper.class);
        List<User> users = userMapper.selectAllUser();
        for (User user : users) {
            System.out.println(user);
        }
    }
}

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