spring整合mybatis

所需配置：

 <dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version><scope>test</scope></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.30</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.13</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>6.0.10</version></dependency>
<!--        spring操作数据库，需要spring-jdbc--><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>6.0.10</version></dependency><dependency><groupId>org.aspectj</groupId><artifactId>aspectjweaver</artifactId><version>1.9.4</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>3.0.2</version></dependency></dependencies>

使用mybatis步骤

1.编写实体类

package com.heerlin.pojo;import lombok.Data;@Data
public class User {private int id;private String name;private String pwd;
}

常用的几个注解：
@Data ： 注在类上，提供类的get、set、equals、hashCode、canEqual、toString方法
@AllArgsConstructor ： 注在类上，提供类的全参构造
@NoArgsConstructor ： 注在类上，提供类的无参构造
@Setter ： 注在属性上，提供 set 方法
@Getter ： 注在属性上，提供 get 方法
@EqualsAndHashCode ： 注在类上，提供对应的 equals 和 hashCode 方法
@Log4j/@Slf4j ： 注在类上，提供对应的 Logger 对象，变量名为 log
 

2.编写核心配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration><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=false&amp;useUnicode=true&amp;characterEncoding=UTF-8"/><property name="username" value="root"/><property name="password" value="zll20021022."/></dataSource></environment></environments><mappers><mapper class="com.heerlin.mapper.UserMapper"/></mappers>
</configuration>

3.编写接口

package com.heerlin.mapper;import com.heerlin.pojo.User;import java.util.List;public interface UserMapper {public List<User> selectUser();
}

4.编写Mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.heerlin.mapper.UserMapper"><select id="selectUser" resultType="com.heerlin.pojo.User">select * from mybatis.user;</select></mapper>

5.测试

import com.heerlin.mapper.UserMapper;
import com.heerlin.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;import java.io.IOException;
import java.io.InputStream;
import java.util.List;public class MyTest {@Testpublic void test() throws IOException{String resources="mybatis-config.xml";InputStream in = Resources.getResourceAsStream(resources);SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(in);SqlSession sqlSession = sessionFactory.openSession(true);UserMapper mapper = sqlSession.getMapper(UserMapper.class);List<User> userList=mapper.selectUser();for (User user : userList) {System.out.println(user);}sqlSession.close();}
}

那么mybatis-spring怎么写呢？

 引入Spring配置文件beans.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"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsd">

 配置数据源替换mybaits的数据源 

<!--配置数据源：数据源有非常多，可以使用第三方的，也可使使用Spring的-->
<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&amp;useUnicode=true&amp;characterEncoding=utf8"/><property name="username" value="root"/><property name="password" value="123456"/>
</bean>

 配置SqlSessionFactory，关联MyBatis

<!--配置SqlSessionFactory-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><property name="dataSource" ref="dataSource"/><!--关联Mybatis--><property name="configLocation" value="classpath:mybatis-config.xml"/><property name="mapperLocations" value="classpath:com/kuang/dao/*.xml"/>
</bean>

 注册sqlSessionTemplate，关联sqlSessionFactory；

<!--注册sqlSessionTemplate , 关联sqlSessionFactory-->
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate"><!--利用构造器注入--><constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>

 增加Dao接口的实现类；私有化sqlSessionTemplate

public class UserDaoImpl implements UserMapper {//sqlSession不用我们自己创建了，Spring来管理private SqlSessionTemplate sqlSession;public void setSqlSession(SqlSessionTemplate sqlSession) {this.sqlSession = sqlSession;}public List<User> selectUser() {UserMapper mapper = sqlSession.getMapper(UserMapper.class);return mapper.selectUser();}
}

 注册bean实现

<bean id="userDao" class="com.kuang.dao.UserDaoImpl"><property name="sqlSession" ref="sqlSession"/>
</bean>

 测试

    @Testpublic void test2(){ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");UserMapper mapper = (UserMapper) context.getBean("userDao");List<User> user = mapper.selectUser();System.out.println(user);}

 结果成功输出！现在我们的Mybatis配置文件的状态！发现都可以被Spring整合！

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration><typeAliases><package name="com.kuang.pojo"/></typeAliases>
</configuration>