Spring事务管理

       Aop的使用使得Spring事务管理更加具有灵活性，已使得事务的提交更加合理化了，Spring和Hibernate结合的时候，我们知道SessionFactory是由Spring提供的，因此，事务自然而然也应该由Spring管理。Spring配置文件中关于事务配置总是由三个组成部分，分别是DataSource、TransactionManager和代理机制这三部分，无论哪种配置方式，一般变化的只是代理机制这部分。

Spring-Hibernate.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:aop="http://www.springframework.org/schema/aop"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
	<bean id="jdbc"
		class="org.springframework.jdbc.datasource.DriverManagerDataSource">
		<property name="driverClassName" value="oracle.jdbc.OracleDriver" />
		<property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" />
		<property name="username" value="scott" />
		<property name="password" value="accp" />
	</bean>
	<bean id="datasource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
		destroy-method="close">
		<property name="driverClass" value="oracle.jdbc.OracleDriver" />
		<property name="jdbcUrl" value="jdbc:oracle:thin:@localhost:1521:orcl" />
		<property name="user" value="scott" />
		<property name="password" value="accp" />
		<!-- 指定连接数据库连接池的最大连接数 -->
		<property name="maxPoolSize" value="20" />
		<!-- 指定连接数据库连接池的最小连接数 -->
		<property name="minPoolSize" value="1" />
		<!-- 指定连接数据库连接池的初始化连接数 -->
		<property name="initialPoolSize" value="5" />
		<!-- 指定连接数据库连接池的连接的最大空闲时间 -->
		<property name="maxIdleTime" value="20" />
	</bean>

	<bean id="sessionFactory"
		class="org.springframework.orm.hibernate3.LocalSessionFactoryBean" scope="singleton">
		<property name="dataSource" ref="datasource">
		</property>
		<property name="mappingResources">
			<list>
				<value>org/han/entity/Log.hbm.xml</value>
				<value>org/han/entity/User.hbm.xml</value>
			</list>
		</property>
		<property name="hibernateProperties">
			<props>
				<prop key="hibernate.show_sql">true</prop>
				<prop key="hibernate.format_sql">true</prop>
				<prop key="hibernate.dialect">org.hibernate.dialect.Oracle9Dialect</prop>
				<prop
					key="hibernate.current_session_context_class">org.springframework.orm.hibernate3.SpringSessionContext</prop><!-- Spring默认值，相当于手动管理事务的<prop key="hibernate.current_session_context_class">thread</prop> -->
			</props>
		</property>
	</bean>
	<bean id="transactionManager"
		class="org.springframework.orm.hibernate3.HibernateTransactionManager">
		<property name="sessionFactory">
			<ref bean="sessionFactory" />
		</property>
	</bean>
	<tx:advice id="txAdvice" transaction-manager="transactionManager"><!-- 事务管理器 -->
		<tx:attributes>
			<tx:method name="login" propagation="REQUIRED" />
		</tx:attributes>
	</tx:advice>
	<aop:config>
		<aop:pointcut
			expression="execution(* org.han.service.*.*(..))"
			id="pointcut" />
		<aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut" />
	</aop:config>
</beans>

Spring-beans.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:aop="http://www.springframework.org/schema/aop"
	xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">

	<import resource="Spring-Hibernate.xml" />
	<bean id="base" class="org.han.dao.BaseDao" abstract="true">
		<property name="sessionFactory" ref="sessionFactory" />
	</bean>
	<bean id="userdao" class="org.han.dao.impl.UserDaoImpl" parent="base">
	</bean>
	<bean id="logdao" class="org.han.dao.impl.LogDaoImpl" parent="base">
	</bean>
</beans>

上面的例子中，我sessionFactory作为了BaseDao的一个属性，所有的Dao继承BaseDao,从BaseDao抽象类中得到 sessionFactory

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import org.hibernate.SessionFactory;

public abstract class BaseDao<T>{
	private Class entityClass;
	protected SessionFactory sessionFactory;

	public SessionFactory getSessionFactory() {
		return sessionFactory;
	}

	public void setSessionFactory(SessionFactory sessionFactory) {
		this.sessionFactory = sessionFactory;
	}

	public BaseDao() {
		super();
		// TODO Auto-generated constructor stub
		entityClass = getParameterizedType(this.getClass());
	}

	/*
	 * 获得当前类的Class
	 */
	private Class getParameterizedType(Class c) {
		Type type = c.getGenericSuperclass();
		ParameterizedType parametType = null;
		if (type instanceof ParameterizedType) {
			parametType = (ParameterizedType) type;
		} else {
			try {
				throw new Exception("not find ParameterizedType!");
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		Type[] types = parametType.getActualTypeArguments();
		return (Class) types[0];
	}

	/*
	 * 通用通过ID获得实体类的方法
	 */
	protected T getEntityById(Integer primaryKey) {
		T t = (T) this.sessionFactory.getCurrentSession().get(this.entityClass, primaryKey);
		return t;
	}
	/*
	 * 公用的save方法
	 */
	public int saveObject(Object obj){
		return (Integer)this.sessionFactory.getCurrentSession().save(obj);
	}
}