声明事务可以省去手动添加事务以及异常处理的麻烦。
注解方式：
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="
xsi:schemaLocation="http://www.springframework.org/schema/beans
">
<context:annotation-config />
<context:component-scan base-package="com.bjsxt" />
<!--
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/spring" />
<property name="username" value="root" />
<property name="password" value="bjsxt" />
</bean>
-->
<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<value>classpath:jdbc.properties</value>
</property>
</bean>
<bean id="dataSource" destroy-method="close"
class="org.apache.commons.dbcp.BasicDataSource">
<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="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="annotatedClasses">
<list>
<value>com.bjsxt.model.User</value>
<value>com.bjsxt.model.Log</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">
org.hibernate.dialect.MySQLDialect
</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
<bean id="txManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<tx:annotation-driven transaction-manager="txManager"/>
</beans>
package com.bjsxt.service;
import javax.annotation.Resource;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import com.bjsxt.dao.LogDAO;
import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.Log;
import com.bjsxt.model.User;
@Component("userService")
public class UserService {
private UserDAO userDAO;
private LogDAO logDAO;
public void init() {
System.out.println("init");
}
public User getUser(int id) {
return null;
}
@Transactional//加上之后相当于自动在其前后添加了事务和try。
public void add(User user) {
userDAO.save(user);
Log log = new Log();
log.setMsg("a user saved!");
logDAO.save(log);
}
public UserDAO getUserDAO() {
return userDAO;
}
@Resource(name="u")
public void setUserDAO( UserDAO userDAO) {
this.userDAO = userDAO;
}
public LogDAO getLogDAO() {
return logDAO;
}
@Resource
public void setLogDAO(LogDAO logDAO) {
this.logDAO = logDAO;
}
public void destroy() {
System.out.println("destroy");
}
}
import javax.annotation.Resource;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.stereotype.Component;
import com.bjsxt.dao.LogDAO;
import com.bjsxt.model.Log;
@Component("logDAO")
public class LogDAOImpl implements LogDAO {
private SessionFactory sessionFactory;
public SessionFactory getSessionFactory() {
return sessionFactory;
}
@Resource
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
public void save(Log log) {
Session s = sessionFactory.getCurrentSession();
s.save(log);
//throw new RuntimeException("error!");
}
}
xml方式：
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
> <context:annotation-config />
<context:component-scan base-package="com.bjsxt" />
<!--
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/spring" />
<property name="username" value="root" />
<property name="password" value="bjsxt" />
</bean>
-->
<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<value>classpath:jdbc.properties</value>
</property>
</bean>
<bean id="dataSource" destroy-method="close"
class="org.apache.commons.dbcp.BasicDataSource">
<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="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<!--
<property name="annotatedClasses">
<list>
<value>com.bjsxt.model.User</value>
<value>com.bjsxt.model.Log</value>
</list>
</property>
-->
<property name="packagesToScan">
<list>
<value>com.bjsxt.model</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">
org.hibernate.dialect.MySQLDialect
</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
<bean id="txManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<aop:config>
<aop:pointcut id="bussinessService"
expression="execution(public * com.bjsxt.service..*.*(..))" />
<aop:advisor pointcut-ref="bussinessService"
advice-ref="txAdvice" />
</aop:config>
<tx:advice id="txAdvice" transaction-manager="txManager">
<tx:attributes>
<tx:method name="getUser" read-only="true" />
<tx:method name="add*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>
</beans>
@Transactional(propagation=Propagation.REQUIRED) 和 @Transactional是一样?
ServiceA {
/**
* 事务属性配置为 PROPAGATION_REQUIRED
*/
void methodA() {
ServiceB.methodB();
}
}
ServiceB {
/**
* 事务属性配置为 PROPAGATION_REQUIRED
*/
void methodB() {
}
}
PROPAGATION_REQUIRED
加入当前正要执行的事务不在另外一个事务里，那么就起一个新的事务
比如说，ServiceB.methodB的事务级别定义为PROPAGATION_REQUIRED, 那么由于执行ServiceA.methodA的时候，
ServiceA.methodA已经起了事务，这时调用ServiceB.methodB，ServiceB.methodB看到自己已经运行在ServiceA.methodA
的事务内部，就不再起新的事务。而假如ServiceA.methodA运行的时候发现自己没有在事务中，他就会为自己分配一个事务。
这样，在ServiceA.methodA或者在ServiceB.methodB内的任何地方出现异常，事务都会被回滚。即使ServiceB.methodB的事务已经被提交，但是ServiceA.methodA在接下来fail要回滚，ServiceB.methodB也要回滚
/**
* 如果ServiceB.methodB出现异常,会影响到ServiceA.methodA的提交么?
*/
