Spring学习笔记-Spring整合Mybatis
创建项目&搭建环境
导入依赖(jar包)
- junit
- mybatis
- mysql数据库
- spring相关
- aop织入
- mybatis-spring【叮!获得新知识点】
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.22</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>5.3.9</version>
</dependency>
<!--Spring操作数据库-->
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.3.9</version>
</dependency>
<!--AOP织入-->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>1.8.14</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.14</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>
</dependencies>
编写实体类(数据库数据略)
package cn.iris.pojo;
/**
* @author Iris 2021/8/13
*/
public class User {
private int id;
private String name;
private String pwd;
public User() {
}
public User(int id, String name, String pwd) {
this.id = id;
this.name = name;
this.pwd = pwd;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", pwd='" + pwd + '\'' +
'}';
}
}
编写interface UserMapper(略)&UserMapper.xml
<?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="cn.iris.mapper.UserMapper">
<select id="selectUser" resultType="User">
SELECT * FROM user;
</select>
</mapper>
编写配置文件【mybatis-config】
<?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>
<properties resource="db.properties"/>
<typeAliases>
<package name="cn.iris.pojo"/>
</typeAliases>
<environments default="mybatis">
<environment id="mybatis">
<transactionManager type="JDBC"/><!-- 单独使用时配置成MANAGED没有事务 -->
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper class="cn.iris.mapper.UserMapper"/>
</mappers>
</configuration>
【tip】解决资源扫描问题
在pom.xml文件中加入以下语句
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
<!-- 由于修改了默认的resource目录,导致src/main/resources的所有文件都不能被扫描,因此还要配多一个 -->
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
</build>
整合Spring方式一
由Spring接管Myabtis业务
- 【spring-mapper.xml】:负责Mybatis的mapper注册,数据库连接以及sqlSession的创建(使用Spring的SqlSessionTemplate)
<?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/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean class="cn.iris.pojo.User"/>
<!--Datasource 使用Spring的数据源替换Mybatis的配置-->
<bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=Asia/Shanghai"/>
<property name="username" value="root"/>
<property name="password" value="123456"/>
</bean>
<!--SqlSessionFactory-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="datasource"/>
<!--绑定mybatis-config+mapper-->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<property name="mapperLocations" value="cn/iris/mapper/UserMapper.xml"/>
</bean>
<!--SqlSessionTemplate 等同于SqlSessionFactory-->
<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
<!--只能使用构造器注入sqlSessionFactory(没有Setter)-->
<constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>
<!---->
<bean id="userMapper" class="cn.iris.mapper.UserMapperImpl">
<property name="sqlSession" ref="sqlSessionTemplate"/>
</bean>
</beans>
- 【applicationConfig.xml】:Spring全局配置
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<import resource="spring-mapper.xml"/>
</beans>
- 【mybatis-config.xml】:由Spring接管后,只需保留别名设置以及部分核心设置(日志、驼峰命名...)内容
<?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="cn.iris.pojo"/>
</typeAliases>
<!-- <settings>-->
<!-- <setting name="" value=""/>-->
<!-- </settings>-->
</configuration>
- 【Class UsermapperImpl】:继承InterFace UserMapper,完成SQlSessionTemplate执行sql操作
package cn.iris.mapper;
import cn.iris.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;
import java.util.List;
/**
* @author Iris 2021/8/13
*/
public class UserMapperImpl implements UserMapper{
// 之前:所有操作都用SQLSession执行
// 现在:都由SqlSessionTemplate执行
private SqlSessionTemplate sqlSession;
public void setSqlSession(SqlSessionTemplate sqlSession) {
this.sqlSession = sqlSession;
}
@Override
public List<User> selectUser() {
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
return mapper.selectUser();
}
}
【测试】
@Test
public void selectUser() throws IOException {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("spring-mapper.xml");
UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
List<User> users = userMapper.selectUser();
for ( User user : users) {
System.out.println(user);
}
}
}
整合Spring方式二
【SqlSessionDaoSupport(Spring5.2及以上版本支持)】
- Class UserMapperImp2
package cn.iris.mapper;
import cn.iris.pojo.User;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import java.util.List;
/**
* @author Iris 2021/8/13
*/
public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper{
@Override
public List<User> selectUser() {
return getSqlSession().getMapper(UserMapper.class).selectUser();
}
}
- 在applicationConfig.xml中注册Bean
<bean id="userMapper2" class="cn.iris.mapper.UserMapperImpl2">
<property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>
- 测试
@Test
public void selectUser() throws IOException {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationConfig.xml");
UserMapper userMapper = context.getBean("userMapper2", UserMapper.class);
List<User> users = userMapper.selectUser();
for ( User user : users) {
System.out.println(user);
}
}