目录
14、Spring整合Mybatis
官方参考文档：http://mybatis.org/spring/zh/index.html
问题：
（1）为什么要整合Mybatis？
整合之前：我们想要拿到Dao层的对象，必须手动通过SQLSessionFactory来创建
整合之后：我们想要拿到直接通过IOC容器拿到
参考：https://www.sohu.com/a/285808583_194621
1、使用SqlSessionTemplate
步骤：
14.1.1、导入依赖
所需依赖：
- Junit：测试所需依赖包
- Lombok：简化实体类get、set等方法
- 引入Spring相关依赖
- 引入mybatis依赖
- 连接数据库的驱动
- Spring整合mybatis所需依赖包
- 使用c3p0数据源
<dependencies>
<!-- 引入Junit测试类 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<!-- 引入LomBok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.12</version>
</dependency>
<!-- 引入Spring相关依赖 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>
<!-- 引入Mybatis依赖 -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.6</version>
</dependency>
<!-- 引入连接数据库的驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.19</version>
</dependency>
<!-- Spring整合Mybatis的依赖包 -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.2</version>
</dependency>
<!-- 使用c3p0数据源 -->
<dependency>
<groupId>c3p0</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.1.1</version>
</dependency>
<!-- Spring对jdbc的封装 -->
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>
</dependencies>
<!-- 特别注意：必须放过该部分资源，不然不会被编译 -->
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>
</resources>
</build>
14.1.2、编写User实体类
@Data
public class User {
private int id;
private int score;
private String name;
}
14.1.3、编写Dao和配置文件xml
public interface UserDao {
List<User> selectAll();
}
<?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.ch.dao.UserDao">
<select id="selectAll" resultType="user">
select * from student;
</select>
</mapper>
14.1.4、编写mybatis配置文件
mybatis一般编写别名和配置【个人习惯】
<?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>
<!-- 设置 -->
<!-- 配置别名 -->
<typeAliases>
<typeAlias type="com.ch.pojo.User" alias="user"/>
<package name="com.ch.pojo"/>
</typeAliases>
</configuration>
14.1.5、编写jdbc.properties
mysql.driver=com.mysql.cj.jdbc.Driver
mysql.url=jdbc:mysql://localhost:3306/mysqlstudy?serverTimezone=GMT&useSSL=true
mysql.username=root
mysql.password=root
14.1.6、编写spring-mybatis.xml
整合还需要一个Dao的实现类14.1.7
<?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
http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 引入外部属性文件 -->
<context:property-placeholder location="jdbc.properties"/>
<!-- 配置数据源 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.DriverManagerDataSource">
<property name="driverClass" value="${mysql.driver}"/>
<property name="jdbcUrl" value="${mysql.url}"/>
<property name="user" value="${mysql.username}"/>
<property name="password" value="${mysql.password}"/>
</bean>
<!-- <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">-->
<!-- <property name="driverClassName" value="${mysql.driver}"/>-->
<!-- <property name="url" value="${mysql.url}"/>-->
<!-- <property name="username" value="${mysql.username}"/>-->
<!-- <property name="password" value="${mysql.password}"/>-->
<!-- </bean>-->
<!-- 配置SqlSessionFactory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<!-- 关联mybatis配置文件 -->
<property name="configLocation" value="mybatis-config.xml"/>
<!-- 添加映射器 -->
<property name="mapperLocations" value="classpath:com/ch/dao/*.xml"/>
</bean>
<!-- 通过配置好的SQLSessionFactory配置SqlSessionTemplate -->
<!-- 没有set方法，只能通过构造器注入 -->
<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
<constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>
<!-- 注入实现类 -->
<bean id="userDaoImpl" class="com.ch.dao.impl.UserDaoImpl">
<property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
</bean>
</beans>
14.1.7、编写实现类
public class UserDaoImpl implements UserDao {
private SqlSessionTemplate sqlSessionTemplate;
public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
this.sqlSessionTemplate = sqlSessionTemplate;
}
@Override
public List<User> selectAll() {
List<User> users = sqlSessionTemplate.getMapper(UserDao.class).selectAll();
return users;
}
}
14.1.8、测试
@Test
public void test(){
ApplicationContext context = new ClassPathXmlApplicationContext("spring-mybatis.xml");
UserDao userDao = context.getBean("userDaoImpl", UserDao.class);
List<User> users = userDao.selectAll();
for (User user : users) {
System.out.println(user);
}
}
常见问题
1、缺少spring-jdbc
使用jdbc数据源
Caused by: java.lang.ClassNotFoundException: org.springframework.jdbc.datasource.DriverManagerDataSource
使用c3p0数据源
Caused by: org.springframework.beans.PropertyBatchUpdateException; nested PropertyAccessExceptions (1) are:
PropertyAccessException 1: org.springframework.beans.MethodInvocationException: Property 'dataSource' threw exception; nested exception is java.lang.NoClassDefFoundError: org/springframework/jdbc/datasource/TransactionAwareDataSourceProxy
at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:122)
at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:77)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1732)
... 35 more
2、未放过java下的.xml配置文件
org.apache.ibatis.binding.BindingException: Type interface com.ch.dao.UserDao is not known to the MapperRegistry.
at org.apache.ibatis.binding.MapperRegistry.getMapper(MapperRegistry.java:47)
at org.apache.ibatis.session.Configuration.getMapper(Configuration.java:745)
at org.mybatis.spring.SqlSessionTemplate.getMapper(SqlSessionTemplate.java:318)
at com.ch.dao.impl.UserDaoImpl.selectAll(UserDaoImpl.java:19)
at MyTest.test(MyTest.java:15)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
解决
2、使用SqlSessionDaoSupport
方式2直接跳过SqlSessionTemplate，使用SQLSessionFactory来实现
修改的地方如下：
1、spring-mybatis.xml
2、实现类
3、总结
