事务注解的方式,相对xml的方式来说,有优点,无需配置需要事务的业务方法的切点和事务属性。但是也有缺点,就是需要在每个需要事务的业务方法上加上一个注解@Transaction,否则事务不会生效。
这里沿用之前spring事务管理的代码:
pom.xml依赖部分:
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.13</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>4.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>4.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>
</dependencies>
jdbc.properties
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///shop?useUnicode=true&useSSL=false
jdbc.username=hadoop
jdbc.password=hadoop
spring.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:context="http://www.springframework.org/schema/context"
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-4.3.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.3.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
<context:property-placeholder location="classpath:jdbc.properties"/>
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${jdbc.driverClassName}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<bean id="accountDao" class="com.xxx.springtransaction.dao.impl.AccountDaoImpl">
<property name="dataSource" ref="dataSource"/>
</bean>
<bean id="accountService" class="com.xxx.springtransaction.service.impl.AccountServiceImpl">
<property name="accountDao" ref="accountDao"></property>
</bean>
<bean id="transactionManager" class="org.springframework.jdbc.datasource
.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<!-- spring transaction annotation -->
<tx:annotation-driven transaction-manager="transactionManager"/>
</beans>
AccountDao.java
package com.xxx.springtransaction.dao;
public interface AccountDao {
public void transferIn(String id,Double money);
public void transferOut(String id,Double money);
public Double findById(String id);
}
AccountDaoImpl.java
package com.xxx.springtransaction.dao.impl;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import com.xxx.springtransaction.dao.AccountDao;
public class AccountDaoImpl extends JdbcDaoSupport implements AccountDao {
@Override
public void transferIn(String id, Double money) {
String sql = "update account set money = money + ? where id = ?";
getJdbcTemplate().update(sql, money,id);
}
@Override
public void transferOut(String id, Double money) {
String sql = "update account set money = money - ? where id = ?";
getJdbcTemplate().update(sql, money,id);
}
@Override
public Double findById(String id){
return null;
}
}
AccountService.java
package com.xxx.springtransaction.service;
public interface AccountService {
public void transfer(String out,String in,Double money);
public Double findById(String id);
}
AccountServiceImpl.java
package com.xxx.springtransaction.service.impl;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.annotation.Transactional;
import com.xxx.springtransaction.dao.AccountDao;
import com.xxx.springtransaction.service.AccountService;
@Transactional
public class AccountServiceImpl implements AccountService {
private AccountDao accountDao;
public void setAccountDao(AccountDao accountDao) {
this.accountDao = accountDao;
}
@Override
public void transfer(String out, String in, Double money) {
accountDao.transferOut(out, money);
//int i = 1/0;
//System.out.println(i);
accountDao.transferIn(in, money);
}
@Override
public Double findById(String id){
return accountDao.findById(id);
}
}
测试类:
package com.xxx.springtransaction;
import javax.annotation.Resource;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import com.xxx.springtransaction.service.AccountService;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring.xml")
public class SpringTransactionTest {
@Resource
private AccountService accountService;
@Test
public void demo1(){
accountService.transfer("1", "2", 200d);
}
}
注解式事务管理的重点是:启用事务注解驱动和在业务类中添加事务注解@Transactional
<tx:annotation-transaction transaction-manager="transactionManager"/>
@Transactional
第一次测试,不使用事务,我们将AccountServiceImpl.java中的导致异常的两行代码注释掉,并且注释@Transactional,然后测试转账,发现是可以成功的。aaa给bbb转账200元,最后aaa的账户800元,bbb的账户1200元。
第二次测试,我们将AccountServiceImpl.java中的导致异常的两行代码去掉注释,然后测试转账,发现是不能全部成功。aaa给bbb转账200元,最后aaa的账户600元,bbb的账户还是1200元,钱转丢了。
第三次测试,将第一次测试中,业务层注释的事务注解@Transactional打开,再次测试转账,aaa向bbb转账200元,结果因为异常,aaa的账户还是600元,bbb的账户还是1200元,没有发生第二步中的钱转丢的情况,因为异常情况下,事务回滚了。所以转账操作一个也没有成功,说明注解式事务生效了。
对于spring事务管理而言,如果是springmvc的项目,倾向于使用xml配置的方式,如果是springboot了,只能使用注解的方式。