事務注解的方式，相對xml的方式來說，有優點，無需配置需要事務的業務方法的切點和事務屬性。但是也有缺點，就是需要在每個需要事務的業務方法上加上一個注解@Transaction，否則事務不會生效。
這裡沿用之前spring事務管理的代碼：
pom.xml依賴部分：
<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);
}
}
測試類：
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);
}
}
注解式事務管理的重點是：啟用事務注解驅動和在業務類中添加事務注解@Transactional
<tx:annotation-transaction transaction-manager="transactionManager"/>
@Transactional
第一次測試，不使用事務，我們将AccountServiceImpl.java中的導緻異常的兩行代碼注釋掉，并且注釋@Transactional，然後測試轉賬，發現是可以成功的。aaa給bbb轉賬200元，最後aaa的賬戶800元，bbb的賬戶1200元。
第二次測試，我們将AccountServiceImpl.java中的導緻異常的兩行代碼去掉注釋，然後測試轉賬，發現是不能全部成功。aaa給bbb轉賬200元，最後aaa的賬戶600元，bbb的賬戶還是1200元，錢轉丢了。
第三次測試，将第一次測試中，業務層注釋的事務注解@Transactional打開，再次測試轉賬，aaa向bbb轉賬200元，結果因為異常，aaa的賬戶還是600元，bbb的賬戶還是1200元，沒有發生第二步中的錢轉丢的情況，因為異常情況下，事務復原了。是以轉賬操作一個也沒有成功，說明注解式事務生效了。
對于spring事務管理而言，如果是springmvc的項目，傾向于使用xml配置的方式，如果是springboot了，隻能使用注解的方式。
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