Spring中通常有两种方式整合MyBtis,一种是通过在xml中配置SqlSession,另一种是定义一个继承SqlSessionDaoSupport的类。
会用到的maven依赖:
<dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.26</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.7</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.3.12</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.3.12</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.9.7</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>2.0.6</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.20</version> </dependency> </dependencies>
直接贴示例,详细解释请看注释。
MyBtis部分代码
实体类:
package com.yun.pojo; import lombok.Data; @Data public class User { private int id; private String name; private String pwd; }
mapper接口:
package com.yun.mapper; import com.yun.pojo.User; import java.util.List; public interface UserMapper { public List<User> selectUser(); }
mapper对应的xml配置:
<?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.yun.mapper.UserMapper"> <select id="selectUser" resultType="user"> select * from mybatis.user; </select> </mapper>
MyBtis的xml配置:
<?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> <typeAliases> <package name="com.yun.pojo"/> </typeAliases> <!-- 以下配置已经在Spring的xml中配置,就不用重复配置了 --> <!-- <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="com.mysql.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&useUnicode=true&characterEncoding=UTF-8"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> <mappers> <mapper class="com.yun.mapper.UserMapper"/> </mappers> --> </configuration>
Spring整合MyBtis代码
Spring的xml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:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd"> <!-- 使用Spring的数据源替换MyBatis的配置,这里使用Spring提供的JDBC, 这样就不用在MyBatis的xml中来配置数据源了--> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&useUnicode=true&characterEncoding=UTF-8"/> <property name="username" value="root"/> <property name="password" value="123456"/> </bean> <!-- 使用Spring配置来创建sqlSessionFactory,不再单独写一个公共方法来创建sqlSessionFactory了 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <!-- 绑定MyBatis相关配置,这里需要注意classpath:后面没有空格 --> <property name="configLocation" value="classpath:mybatis-config.xml"/> <property name="mapperLocations" value="classpath:com/yun/mapper/*.xml"/> </bean> <!-- Spring的SqlSessionTemplate就相当于MyBatis中的SqlSession对象, 并且由于SqlSessionTemplate没有对应的set方法,所以只能使用构造器进行注入 --> <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate"> <constructor-arg index="0" ref="sqlSessionFactory"/> </bean> <bean id="userMapper" class="com.yun.mapper.UserMapperImpl"> <property name="sqlSession" ref="sqlSession"/> </bean> </beans>
Spring实现类:
package com.yun.mapper; import com.yun.pojo.User; import org.mybatis.spring.SqlSessionTemplate; import java.util.List; public class UserMapperImpl implements UserMapper{ private SqlSessionTemplate sqlSession; public void setSqlSession(SqlSessionTemplate sqlSession) { this.sqlSession = sqlSession; } // 将该类通过Spring注入之后,直接使用此方法即可获得数据库查询结果 public List<User> selectUser() { UserMapper mapper = sqlSession.getMapper(UserMapper.class); return mapper.selectUser(); } }
测试:
import com.yun.mapper.UserMapper; import com.yun.pojo.User; import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class MyTest { @Test public void test(){ ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml"); UserMapper userMapper = context.getBean("userMapper", UserMapper.class); for (User user : userMapper.selectUser()) { System.out.println(user); } } }
输出:
User(id=1, name=ZhangSan, pwd=123456) User(id=2, name=lisi, pwd=123456) User(id=3, name=wangwu, pwd=123456) User(id=4, name=zhaoliu, pwd=123456)
这种方式其实就是第一种方式的简化版,下面只贴一些差异点。
实现类:
package com.yun.mapper; import com.yun.pojo.User; import org.mybatis.spring.support.SqlSessionDaoSupport; import java.util.List; // 需要继承SqlSessionDaoSupport类,并实现对应的mapper接口 public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper { public List<User> selectUser() { // 通过getSqlSession()就可以直接拿到SqlSession对象,不需要再用set方法进行注入 return getSqlSession().getMapper(UserMapper.class).selectUser(); } }
Spring中xml配置:
<!-- 与第一种方式相比,不需要再配置sqlSession,直接在实现类的bean中配置sqlSessionFactory即可 --> <bean id="userMapper2" class="com.yun.mapper.UserMapperImpl2"> <property name="sqlSessionFactory" ref="sqlSessionFactory"/> </bean>