Spring 声明式事务管理

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="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-2.5.xsd
           http://www.springframework.org/schema/aop
           http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
           http://www.springframework.org/schema/tx
           http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
    <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
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-2.5.xsd
           http://www.springframework.org/schema/aop
           http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
           http://www.springframework.org/schema/tx
           http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
    <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?
*/