day54_spring整合mybatis
Spring+Mybatis整合【重点】
Spring学完了,主要学习Spring两个内容:IOC+AOP
利用这两个知识来完成spring和mybatis的整合
- IOC: 控制反转,用来创建对象
- XxxService
- 通过数据源创建数据库连接
- 创建SqlSessionFactory
- 创建SqlSession
- 获得XxxMapper代理对象
- AOP: 面向切面
- 控制事务
具体的整合思路
- 创建项目
- 导入依赖
- spring依赖
- aop依赖
- mybatis依赖
- 数据库驱动依赖
- 连接池依赖
- 日志依赖
专业用于spring整合mybatis依赖spring-jdbc依赖,用于Dao层支持- 配置文件
spring配置文件
- 基本的IOC,DI扫描注解配置
- 加载配置文件
- 配置数据源
- 配置关于Mybatis
- mybatis配置文件
- db配置文件
- log4j配置文件
- 具体的业务代码
- UserService+UserServiceImpl
- UserMapper.java+ UserMapper.xml
- 测试
1.1 创建项目
1.2 依赖
<dependencies>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-contextartifactId>
<version>5.1.6.RELEASEversion>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-aspectsartifactId>
<version>5.1.6.RELEASEversion>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>5.1.6.RELEASEversion>
dependency>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>4.13.1version>
<scope>testscope>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatisartifactId>
<version>3.5.7version>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>5.1.47version>
dependency>
<dependency>
<groupId>log4jgroupId>
<artifactId>log4jartifactId>
<version>1.2.17version>
dependency>
<dependency>
<groupId>com.github.pagehelpergroupId>
<artifactId>pagehelperartifactId>
<version>5.3.0version>
dependency>
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
<version>1.2.8version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatis-springartifactId>
<version>1.3.1version>
dependency>
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
<version>1.18.12version>
dependency>
dependencies>
1.3 配置文件
1.3.1 db.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/java2217?useSSL=false
jdbc.username=root
jdbc.password=123456
jdbc.initialSize=5
jdbc.maxActive=20
jdbc.minIdle=3
jdbc.maxWait=0
jdbc.timeBetweenEvictionRunsMillis=0
jdbc.minEvictableIdleTimeMillis=0
1.3.2 log4j.properties
# ERROR是级别
# 级别从低到高: debug,info,warn,error (日志信息从详细到简单)
# stdout: standard output的缩写,标准输出,其实就是输出到控制台
log4j.rootLogger=error
# 因为整个mybatis日志太多,可以指定只输出自己项目中指定位置的日志
log4j.logger.com.qf.mapper=debug,stdout
# 上面的stdout,是跟此处的stdout一样
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
1.3.3 mybatis-config.xml
DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<settings>
<setting name="logImpl" value="LOG4J"/>
<setting name="mapUnderscoreToCamelCase" value="true"/>
<setting name="cacheEnabled" value="true"/>
settings>
configuration>
1.3.4 applicationContext.xml
<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"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="com.qf"/>
<context:property-placeholder location="classpath:db.properties" />
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
<property name="initialSize" value="${jdbc.initialSize}"/>
<property name="maxActive" value="${jdbc.maxActive}"/>
<property name="minIdle" value="${jdbc.minIdle}"/>
<property name="maxWait" value="${jdbc.maxWait}"/>
<property name="timeBetweenEvictionRunsMillis" value="${jdbc.timeBetweenEvictionRunsMillis}"/>
<property name="minEvictableIdleTimeMillis" value="${jdbc.minEvictableIdleTimeMillis}"/>
bean>
<bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="typeAliasesPackage" value="com.qf.model"/>\
<property name="plugins">
<set>
<bean class="com.github.pagehelper.PageInterceptor">
<property name="properties">
<props>
<prop key="helperDialect">mysqlprop>
props>
property>
bean>
set>
property>
<property name="configLocation" value="mybatis-config.xml"/>
bean>
<bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="sqlSessionFactoryBeanName" value="sessionFactory"/>
<property name="basePackage" value="com.qf.mapper"/>
bean>
beans>
1.4 业务类
1.4.1 业务层
public interface UserService {
User findUserById(int id);
}
@Service
public class UserServiceImpl implements UserService {
// 注入Mapper
@Autowired
private UserMapper userMapper;
@Override
public User findUserById(int id) {
return userMapper.findUserById(id);
}
}
1.4.2 数据层
public interface UserMapper {
User findUserById(int id);
}
DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.qf.mapper.UserMapper">
<select id="findUserById" resultType="User">
SELECT
*
FROM
tb_user
WHERE
id = #{id}
select>
mapper>
1.5 测试
@Test
public void test() {
String path = "applicationContext.xml";
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(path);
UserService service = context.getBean("userServiceImpl", UserService.class);
User user = service.findUserById(1);
System.out.println(user );
}
2 事务
2.1 介绍
Spring管理事务,有两种方案
- 编程式事务
- 需要手动给每个方法编写事务代码
- 代码大量冗余,不灵活,对业务代码有侵入性
- 声明式事务【学习】
- 在applicationContext.xml文件中配置aop,声明哪些方法需要事务管理
- 业务代码不用做任何改变,无感的就会有事务管理
2.2 目标方法
AOP编程
- 目标方法
- 定义切面类,定义增强的方法
- 配置文件中"织入"
事务配置
- 目标方法
spring提供了事务管理器,即增强的方法- 配置文件中"织入"
需求: 转账案例
public interface UserService {
// 演示转账
/**
* 由谁转给谁,转多少
* @param outId 转出的人的id
* @param inId 收入的人的id
* @param money 转多少钱
* @return 是否成功
*/
boolean transferMoney(int outId,int inId,double money);
}
/**
* 由谁转给谁,转多少
* @param outId 转出的人的id
* @param inId 收入的人的id
* @param money 转多少钱
* @return 是否成功
*/
@Override
public boolean transferMoney(int outId, int inId, double money) {
// 转出
int i = userMapper.updateAccountDesc(outId,money);
System.out.println(1/0 );// 模拟,出现故障
// 转入
int j = userMapper.updateAccountIncr(inId,money);
if (i >0 && j > 0) {
return true;
}
return false;
}
}
public interface UserMapper {
int updateAccountDesc(@Param("outId") int outId, @Param("money") double money);
int updateAccountIncr(@Param("inId") int inId, @Param("money") double money);
}
<update id="updateAccountDesc">
update account set money = money - #{money} where id = #{outId}
update>
<update id="updateAccountIncr">
update account set money = money + #{money} where id = #{inId}
update>
2.3 配置 【重点】
<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"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<context:component-scan base-package="com.qf"/>
<context:property-placeholder location="classpath:db.properties" />
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
<property name="initialSize" value="${jdbc.initialSize}"/>
bean>
<bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="typeAliasesPackage" value="com.qf.model"/>
<property name="plugins">
<set>
<bean class="com.github.pagehelper.PageInterceptor">
<property name="properties">
<props>
<prop key="helperDialect">mysqlprop>
props>
property>
bean>
set>
property>
<property name="configLocation" value="mybatis-config.xml"/>
bean>
<bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="sqlSessionFactoryBeanName" value="sessionFactory"/>
<property name="basePackage" value="com.qf.mapper"/>
bean>
<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
bean>
<tx:advice id="txAdvice" transaction-manager="txManager">
<tx:attributes>
<tx:method name="transferMoney"/>
<tx:method name="*"/>
tx:attributes>
tx:advice>
<aop:config>
<aop:pointcut id="myPointcut" expression="execution(* com.qf.service.impl.*.*(..))"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="myPointcut"/>
aop:config>
beans>
【重要】关于事务主要是第5,6,7步
2.4 测试
@Test
public void test2() {
String path = "applicationContext.xml";
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(path);
UserService service = context.getBean("userServiceImpl", UserService.class);
boolean b = service.transferMoney(1, 2, 100);
System.out.println(b );
}
2.5 事务属性配置【了解】
隔离级别 isolation=“DEFAULT”
| 属性值 | 解释 |
|---|---|
| DEFAULT | 采用当前数据库默认的级别(建议) |
| READ_UNCOMMITTED | 读未提交 |
| READ_COMMITTED | 读已提交(Oracle默认级别) |
| REPEATABLE_READ | 可重复读(MySQL默认级别) |
| SERIALIZABLE | 串行化 |
传播行为 propagation=“REQUIRED” (默认)
REQUIRED: 不存在外部事务时,就会开启新事物;存在外部事务,则合并事务到外部事务(适合增删改频率比较高方法)
SUPPORTS: 不存在外部事务时,不开启新事物;存在外部事务,则合并事务到外部事务(适合查询的方法)
只读 : read-only=“false” (默认)
- true: 只读,适合查询
- false: 默认值,可以增删改
超时: timeout , 当前事务所需数据被其他事务占用,就等待.
-1: 有数据库指定等待时间(默认)
100: 可以自己指定超时时间,单位是秒
回滚 rollback-for=“RuntimeException” ,默认只有抛出运行时异常,会回滚事务,其他异常会提交事务
可以指定rollback-for=“Exception”,这样所有异常都会回滚事务
3 注解开发事务
注解开发事务,不用编写aop:config和tx:advice,.即第6,7步不用再写
<!-- 1,2,3,4步骤还是需要的,...->
<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
bean>
<tx:annotation-driven transaction-manager="txManager"/>
beans>
哪里需要事务哪里加注解
@Service
@Transactional // 注解加类上,类中所有方法都有事务,加在方法上,只是单独某个方法有事务
public class UserServiceImpl implements UserService {
}
// 事务的属性,也可以在注解中配置
@Transactional(isolation = Isolation.DEFAULT,propagation = Propagation.REQUIRED)
