spring事務管理之二:宣告式事務管理:使用代理方式
spring宣告式事務管理,分為三種方式,分別是:
1、使用代理類TransactionProxyFactoryBean的方式
2、使用aspectj+xml配置的方式
3、使用事務註解的方式
其中後面兩種是比較常用的,使用xml和註解的方式。
這裡介紹使用代理類TransactionProxyFactoryBean的方式:
pom.xml
<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" /> </bean> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource" /> </bean> <!-- spring transaction proxy --> <bean id="accountServiceProxy" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean"> <property name="transactionManager" ref="transactionManager" /> <property name="target" ref="accountService" /> <property name="transactionAttributes"> <props> <prop key="transfer">PROPAGATION_REQUIRED</prop> </props> </property> </bean> </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 com.xxx.springtransaction.dao.AccountDao;
import com.xxx.springtransaction.service.AccountService;
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);
}
}
單元測試類:SpringTransactionTest.java
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(name="accountServiceProxy")
private AccountService accountService;
@Test
public void demo1(){
accountService.transfer("1", "2", 200d);
}
}
代理方式事務管理的重點在於xml配置裡面,需要為target為accountService的目標類配置事務屬性。
在呼叫業務層方法時,需要引入的物件已經不是accountService了,而是變成了代理類accountServiceProxy。
測試事務生效的方法:
1、預設不使用事務,單元測試方法中還是使用@Resource(name="accountService"),並且註釋掉業務層方法的異常程式碼:
int i = 1/0;
System.out.println(i);
aaa向bbb轉賬200元成功,aaa的賬戶變為800,bbb的賬戶變為1200。
2、去掉業務層的異常程式碼註釋,這時候不使用事務,aaa轉賬bbb200元,aaa的賬戶變為600元,但是因為異常,bbb的賬戶並不會增加200元,最終aaa賬戶600,bbb的賬戶1200元,錢轉丟了。
3、使用事務,單元測試類中@Resource(name="accountServiceProxy"),並且去掉業務層異常程式碼的註釋。aaa再次給bbb轉賬,這時候因為異常,而且使用了事務。aaa的賬戶不會減少200元,而且bbb的賬戶也不會增加200元。在測試2的基礎上aaa的賬戶還是600元,bbb的賬戶還是1200元。