整合Mybatis
步骤
- 导入相关jar包
- junit
- mybatis
- mysql数据库
- spring相关知识
- aop织入
- mybatis-spring
环境搭建：
mybatis-spring这个依赖包对于spring和mybatis的版本是有要求的
导入pom文件依赖：
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>Spring_Study</artifactId>
<groupId>org.example</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>Spring_StudyMybatis08</artifactId>
<dependencies>
<!--单元测试-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!--Spring-webmvc-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.3.6</version>
</dependency>
<!--Mysql连接-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.15</version>
</dependency>
<!--Mybatis-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>
<!--SpringJDBC驱动-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.4.RELEASE</version>
</dependency>
<!--mybatis-spring整合Mybatis和Spring-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.1</version>
</dependency>
</dependencies>
<!--解决Mybatis静态资源输出问题-->
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>
- 编写配置文件
mybatis-config.xml
<?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>
<!--创建别名-->
<typeAliases>
<package name="com.test.pojo"/>
</typeAliases>
<!--使用Spring管理-->
<!--<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<!– 配置数据库连接信息 –>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://192.168.23.129:3306/BigData" />
<property name="username" value="root" />
<property name="password" value="123456" />
</dataSource>
</environment>
</environments>-->
<!--注册接口UserMapper.class-->
<!--也可以使用Spring进行管理-->
<!--<mappers>
<mapper class="com.test.mapper.UserMapper"/>
</mappers>-->
</configuration>
spring-mybatis.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/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<!--Datasource:使用Spring的数据源替换Mybatis的配置 c3p0 dbcp等
这里使用Spring提供的JDBC：org.springframework.jdbc.datasource.DriverManagerDataSource
-->
<bean id="Datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.cj.jdbc.Driver" />
<property name="url" value="jdbc:mysql://192.168.23.129:3306/BigData?characterEncoding=UTF-8" />
<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的配置文件-->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<!--对mybatis中的mapper进行管理，mybatis-config.xml中就不用配置了-->
<property name="mapperLocations" value="com/test/mapper/*.xml"/>
</bean>
<!--方式1-->
<!--SqlSessionTemplate：就是我们使用的SQLSession（mybatis-spring内置的）-->
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
<!--只能使用构造器注入，因为它没有set方法-->
<constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>
<!--注入UserMapperImpl-->
<!-- <bean id="userMapperImpl" class="com.test.mapper.UserMapperImpl">-->
<!-- <property name="sqlsession" ref="sqlSession"/>-->
<!-- </bean>-->
<!--方式2，相对方式1少了一步操作-->
<bean id="userMapperImpl" class="com.test.mapper.UserMapperImpl">
<!--这个参数是直接注入给UserMapperIml.clss的父类SQLSessionDaoSupport.class的-->
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>
</beans>
- 测试
User.class
package com.test.pojo;
import lombok.Data;
@Data
public class User {
private int id;
private String name;
private String password;
}
UserMapper.class
package com.test.mapper;
import com.test.pojo.User;
import java.util.List;
public interface UserMapper {
public List<User> selectUser();
}
UserMapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.test.mapper.UserMapper">
<select id="selectUser" resultType="User">
select * from user;
</select>
</mapper>
初期整合spring和mybatis会多出一个实现类，后面将把他去掉
UserMapperImpl.class
package com.test.mapper;
import com.test.pojo.User;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import java.util.List;
public class UserMapperImpl extends SqlSessionDaoSupport implements UserMapper{
//方式1
// private SqlSessionTemplate sqlsession;
//
// public void setSqlsession(SqlSessionTemplate sqlsession) {
// this.sqlsession = sqlsession;
// }
//
// public List<User> selectUser() {
// UserMapper mapper = sqlsession.getMapper(UserMapper.class);
// return mapper.selectUser();
// }
//方式2：需要继承一个类SqlSessionDaoSupport他可以直接getSQLSession，在spring.xml文件的配置中直接少了一步
public List<User> selectUser() {
SqlSession sqlSession = getSqlSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
return mapper.selectUser();
}
}
测试类：MyTest.class
import com.test.mapper.UserMapper;
import com.test.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 org.apache.ibatis.*;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
public class MyTest {
@Test
public void testselectUser() throws IOException {
String mybatis = "mybatis-config.xml";
InputStream resourceAsStream = Resources.getResourceAsStream(mybatis);
SqlSessionFactory build = new SqlSessionFactoryBuilder().build(resourceAsStream);
SqlSession sqlSession = build.openSession(true);
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
List<User> users = mapper.selectUser();
for (User u:users) {
System.out.println(u);
}
}
@Test
public void test2selectUser(){
ApplicationContext context = new ClassPathXmlApplicationContext("spring-mybatis.xml");
UserMapper userMapperImpl = context.getBean("userMapperImpl",UserMapper.class);
List<User> users = userMapperImpl.selectUser();
for (User user:users) {
System.out.println(user);
}
}
}
回忆Mybatis
1.编写实体类
package com.test.pojo;
import lombok.Data;
@Data
public class User {
private int id;
private String name;
private String password;
}
2.编写核心配置文件
<?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>
<!--创建别名-->
<typeAliases>
<package name="com.test.pojo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<!-- 配置数据库连接信息 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://192.168.23.129:3306/BigData" />
<property name="username" value="root" />
<property name="password" value="123456" />
</dataSource>
</environment>
</environments>
<!--注册接口UserMapper.class-->
<mappers>
<mapper class="com.test.mapper.UserMapper"/>
</mappers>
</configuration>
3.编写接口
package com.test.mapper;
import com.test.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 mapper PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.test.mapper.UserMapper">
<select id="selectUser" resultType="User">
select * from user;
</select>
</mapper>
5.测试
import com.test.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 org.apache.ibatis.*;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
public class MyTest {
@Test
public void testselectUser() throws IOException {
String mybatis = "mybatis-config.xml";
InputStream resourceAsStream = Resources.getResourceAsStream(mybatis);
SqlSessionFactory build = new SqlSessionFactoryBuilder().build(resourceAsStream);
SqlSession sqlSession = build.openSession(true);
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
List<User> users = mapper.selectUser();
for (User u:users) {
System.out.println(u);
}
}
}
声明式事务
事务简介
- 把一组业务当成一个业务来做，要么都成功，要么都失败
- 事务在项目开发中，十分的重要，涉及到数据的一致性问题，不能马虎
- 确保数据的完整性和一致性
事务的ACID原则： - 原子性
- 一致性
- 隔离性
- 多个业务可能操作同样一个资源，防止数据损坏
- 持久性
- 事务一旦提交，无论系统发生什么问题，结果都不会再被影响，被持久化的写到存储器中。
Spring中的事务管理
- 声明式事务：AOP
- 编程式事务：需要再代码中，进行事务的管理
为什么需要事务：
- 如果不配置事务，可能存在数据提交不一致的情况
- 如果我们不在Spring中配置事务声明，我们需要在代码中手动配置事务
- 事务在项目开发中十分重要，涉及到数据的完整性和一致性（例如银行转账问题，若网络突然中断，会出现一个人转钱，另一个人却没收到钱的情况）。
测试代码：
User.class
package com.test.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor //有参构造注解
@NoArgsConstructor //无参构造注解
public class User {
private int id;
private String name;
private String password;
}
UserMapper.class
package com.test.mapper;
import com.test.pojo.User;
import java.util.List;
public interface UserMapper {
public List<User> selectUser();
public void addUser(User user);
public void deleteUser(int id);
public void updateUser(int id,String name,String password);
}
UserMapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.test.mapper.UserMapper">
<select id="selectUser" resultType="User">
select * from user;
</select>
<insert id="addUser" parameterType="User">
insert into user values(#{id},#{name},#{password})
</insert>
<delete id="deleteUser" parameterType="int">
deletes from user where id=#{id}
</delete>
<update id="updateUser">
UPDATE user SET NAME = '#{name}',PASSWORD = '#{password}' WHERE id =#{id}
</update>
</mapper>
UserMapperImpl.java
package com.test.mapper;
import com.test.pojo.User;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import java.util.List;
public class UserMapperImpl extends SqlSessionDaoSupport implements UserMapper{
//方式2：需要继承一个类SqlSessionDaoSupport他可以直接getSQLSession，在spring.xml文件的配置中直接少了一步
public List<User> selectUser() {
SqlSession sqlSession = getSqlSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
//测试事务：先加一个用户，在删一个用户，删除命令故意写错，看报错了会不会添加一个用户
User user = new User(7,"www","wwww");
addUser(user);
deleteUser(7);
return mapper.selectUser();
}
public void addUser(User user) {
getSqlSession().getMapper(UserMapper.class).addUser(user);
}
public void deleteUser(int id) {
getSqlSession().getMapper(UserMapper.class).deleteUser(id);
}
public void updateUser(int id, String name, String password) {
getSqlSession().getMapper(UserMapper.class).updateUser(id,name,password);
}
}
配置文件：
applicationContext.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/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<!--导入mybatis和Spring整合的配置文件-->
<import resource="spring-mybatis.xml"></import>
<!--配置bean-->
<bean id="userMapperImpl" class="com.test.mapper.UserMapperImpl">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>
</beans>
mybatis-config.xml
<?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>
<!--创建别名-->
<typeAliases>
<package name="com.test.pojo"/>
</typeAliases>
<!--使用Spring管理-->
<!--<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<!– 配置数据库连接信息 –>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://192.168.23.129:3306/BigData" />
<property name="username" value="root" />
<property name="password" value="123456" />
</dataSource>
</environment>
</environments>-->
<!--注册接口UserMapper.class-->
<!--也可以使用Spring进行管理-->
<!--<mappers>
<mapper class="com.test.mapper.UserMapper"/>
</mappers>-->
</configuration>
spring-mybatis.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"
xmlns:tx="http://www.springframework.org/schema/tx"
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/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd">
<!--Datasource:使用Spring的数据源替换Mybatis的配置 c3p0 dbcp等
这里使用Spring提供的JDBC：org.springframework.jdbc.datasource.DriverManagerDataSource
-->
<bean id="Datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.cj.jdbc.Driver" />
<property name="url" value="jdbc:mysql://192.168.23.129:3306/BigData?characterEncoding=UTF-8" />
<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的配置文件-->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<!--对mybatis中的mapper进行管理，mybatis-config.xml中就不用配置了-->
<property name="mapperLocations" value="com/test/mapper/*.xml"/>
</bean>
<!--方式1-->
<!--SqlSessionTemplate：就是我们使用的SQLSession（mybatis-spring内置的）-->
<!-- <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">-->
<!-- <!–只能使用构造器注入，因为它没有set方法–>-->
<!-- <constructor-arg index="0" ref="sqlSessionFactory"/>-->
<!-- </bean>-->
<!--注入UserMapperImpl-->
<!-- <bean id="userMapperImpl" class="com.test.mapper.UserMapperImpl">-->
<!-- <property name="sqlsession" ref="sqlSession"/>-->
<!-- </bean>-->
<!--方式2，相对方式1少了一步操作-->
<!-- <bean id="userMapperImpl" class="com.test.mapper.UserMapperImpl">-->
<!-- <!–这个参数是直接注入给UserMapperIml.clss的父类SQLSessionDaoSupport.class的–>-->
<!-- <property name="sqlSessionFactory" ref="sqlSessionFactory"></property>-->
<!-- </bean>-->
<!--配置事务:先引入约束-->
<!--配置声明式事务-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="Datasource"></property>
</bean>
<!--配置事务通知-->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<!--配置给特定的方法配置事务
配置事务的传播新特性：propagation="REQUIRED"（如果没有事务则新建一个事务，Spring默认的）
-->
<tx:attributes>
<tx:method name="add" propagation="REQUIRED"/> <!--表示以add打头的方法-->
<tx:method name="delete" propagation="REQUIRED"/>
<tx:method name="update" propagation="REQUIRED"/>
<tx:method name="select" propagation="REQUIRED"/>
<tx:method name="*" propagation="REQUIRED"/> <!--表示所有的方法-->
</tx:attributes>
</tx:advice>
<!--配置AOP，织入事务-->
<aop:config>
<aop:pointcut id="txPointCut" expression="execution(* com.test.mapper.*.*(..))"/>
<!--
pointcut-ref="txPointCut" :织入对象
advice-ref="txAdvice" :要织入的东西
-->
<aop:advisor advice-ref="txAdvice" pointcut-ref="txPointCut"></aop:advisor>
</aop:config>
</beans>
MyTest.java
import com.test.mapper.UserMapper;
import com.test.pojo.User;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.util.List;
public class MyTest {
@Test
public void selectUser(){
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
UserMapper userMapperImpl = context.getBean("userMapperImpl", UserMapper.class);
List<User> userList = userMapperImpl.selectUser();
for (User user:userList) {
System.out.println(user);
}
}
@Test
public void operationUser(){
User user = new User(7,"haha","haha");
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
UserMapper userMapperImpl = context.getBean("userMapperImpl", UserMapper.class);
userMapperImpl.updateUser(6,"haha","haha");
}
}