Spring + Hibernate+SQL2005 实现两个数据库实例跨库DAO事务

最新推荐文章于 2021-02-17 20:53:25 发布

最新推荐文章于 2021-02-17 20:53:25 发布 · 182 阅读

文章标签：

#DAO #Hibernate #Spring #数据结构 #Bean

本文介绍如何使用Spring和Hibernate实现跨数据库实例的事务处理。通过配置两个独立的数据源和会话工厂，结合事务拦截器，实现了不同数据库之间的事务同步。演示了从一个数据库向另一个数据库迁移数据的过程。

开发中需要在同一台数据库服务器上，不同的数据库实例之间，执行跨库的事务。本文给出Spring+Hibernate+SQL2005的例子。

1 Spring配置文件，applicationContext-db.xml：

拦截的类是PersonDS，方法是transferPerson,

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
    "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>

	<bean id="placeholderConfig"
		class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
		<property name="location">
			<value>classpath:db.properties</value>
		</property>
	</bean>

	<bean id="local_dataSource" class="org.apache.commons.dbcp.BasicDataSource">
		<property name="driverClassName" value="${db.driverClassName}" />
		<property name="url" value="${db.url};databaseName=${db.name.local}" />
		<property name="username" value="${db.username}" />
		<property name="password" value="${db.password}" />
	</bean>

	<bean id="local_sessionFactory"
		class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
		<property name="dataSource">
			<ref bean="local_dataSource" />
		</property>
		<property name="mappingResources">
			<list>
				<value>edu/dlut/nihao/lvhl/domain/Person.hbm.xml</value>
			</list>
		</property>
		<property name="hibernateProperties">
			<props>
				<prop key="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</prop>
				<prop key="hibernate.show_sql">true</prop>
			</props>
		</property>
	</bean>

	<!--transactionManager-->
	<bean id="local_transactionManager"
		class="org.springframework.orm.hibernate3.HibernateTransactionManager">
		<property name="sessionFactory">
			<ref local="local_sessionFactory" />
		</property>
	</bean>

	<bean id="local_transactionInterceptor"
		class="org.springframework.transaction.interceptor.TransactionInterceptor">
		<property name="transactionManager" ref="local_transactionManager" />
		<property name="transactionAttributeSource" ref="txAttributeSource" />
	</bean>

	<bean id="txAttributeSource"
		class="org.springframework.transaction.interceptor.NameMatchTransactionAttributeSource">
		<property name="properties">
			<props>
				<prop key="insert*">PROPAGATION_REQUIRED</prop>
				<prop key="save*">PROPAGATION_REQUIRED</prop>
				<prop key="update*">PROPAGATION_REQUIRED</prop>
				<prop key="delete*">PROPAGATION_REQUIRED</prop>
				<prop key="remove*">PROPAGATION_REQUIRED</prop>
				<prop key="cancel*">PROPAGATION_REQUIRED</prop>
				<prop key="create*">PROPAGATION_REQUIRED</prop>
				<prop key="buildXml*">PROPAGATION_REQUIRED</prop>
				<prop key="publish*">PROPAGATION_REQUIRED</prop>
				<prop key="copy*">PROPAGATION_REQUIRED</prop>
				<prop key="list*">PROPAGATION_REQUIRED</prop>
				<prop key="find*">PROPAGATION_REQUIRED</prop>
				<prop key="get*">PROPAGATION_REQUIRED</prop>
				<prop key="deal*">PROPAGATION_REQUIRED</prop>
				<prop key="search*">PROPAGATION_REQUIRED</prop>
				<prop key="is*">PROPAGATION_REQUIRED</prop>
				<prop key="has*">PROPAGATION_REQUIRED</prop>
				<prop key="checkPass*">PROPAGATION_REQUIRED</prop>
				<prop key="changePass*">PROPAGATION_REQUIRED</prop>
				<prop key="login*">PROPAGATION_REQUIRED</prop>
				<prop key="logout*">PROPAGATION_REQUIRED</prop>
				<prop key="transfer*">PROPAGATION_REQUIRED</prop>
			</props>
		</property>
	</bean>
	<bean
		class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
		<property name="beanNames">
			<value>*DS</value>
		</property>
		<property name="interceptorNames">
			<list>
				<value>local_transactionInterceptor</value>
				<value>foreign_transactionInterceptor</value>
			</list>
		</property>
	</bean>

	<bean id="local_personDAO" class="edu.dlut.nihao.lvhl.domain.PersonDAO">
		<property name="sessionFactory">
			<ref bean="local_sessionFactory" />
		</property>
	</bean>

	<bean id="foreign_dataSource" class="org.apache.commons.dbcp.BasicDataSource">
		<property name="driverClassName" value="${db.driverClassName}" />
		<property name="url" value="${db.url};databaseName=${db.name.foreign}" />
		<property name="username" value="${db.username}" />
		<property name="password" value="${db.password}" />
	</bean>

	<bean id="foreign_sessionFactory"
		class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
		<property name="dataSource">
			<ref bean="foreign_dataSource" />
		</property>
		<property name="mappingResources">
			<list>
				<value>edu/dlut/nihao/lvhl/domain/Person.hbm.xml</value>
			</list>
		</property>
		<property name="hibernateProperties">
			<props>
				<prop key="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</prop>
				<prop key="hibernate.show_sql">true</prop>
			</props>
		</property>
	</bean>

	<bean id="foreign_transactionManager"
		class="org.springframework.orm.hibernate3.HibernateTransactionManager">
		<property name="sessionFactory">
			<ref local="foreign_sessionFactory" />
		</property>
	</bean>

	<bean id="foreign_transactionInterceptor"
		class="org.springframework.transaction.interceptor.TransactionInterceptor">
		<property name="transactionManager" ref="foreign_transactionManager" />
		<property name="transactionAttributeSource" ref="txAttributeSource" />
	</bean>

	<bean id="foreign_personDAO" class="edu.dlut.nihao.lvhl.domain.PersonDAO">
		<property name="sessionFactory">
			<ref bean="foreign_sessionFactory" />
		</property>
	</bean>

	<bean id="personDS" class="edu.dlut.nihao.lvhl.domain.PersonDS">
		<property name="foreignDAO" ref="foreign_personDAO"></property>
		<property name="localDAO" ref="local_personDAO"></property>
	</bean>

</beans>

2 数据库属性文件 db.properties

#Created by JInto - www.guh-software.de
#Wed Aug 25 16:36:01 CST 2010
db.driverClassName=com.microsoft.sqlserver.jdbc.SQLServerDriver
db.password=1234
db.port=1433
db.url=jdbc\:sqlserver\://10.87.40.148
db.username=sa
db.name.local=Local
db.name.foreign=Foreign

3 涉及到两个数据库实例，一个叫做Local，另一个叫Foreign。都有一个表Person，结构一样，列ID为主键，assigned属性，定义为：

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Person](
	[Id] [bigint] NOT NULL,
	[Name] [varchar](50) NULL,
 CONSTRAINT [PK_Person] PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF

4 hibernate映射文件，其中列ID为主键，assigned属性。Person.hbm.xml源代码：

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="edu.dlut.nihao.lvhl.domain">

	<class name="edu.dlut.nihao.lvhl.domain.Person" table="Person"
		select-before-update="false" dynamic-update="false" dynamic-insert="false"
		optimistic-lock="version">

		<id name="id" column="Id" type="java.lang.Long" length="19">
			<generator class="assigned"></generator>
		</id>

		<property name="name" type="java.lang.String" update="true"
			insert="true" access="property" column="Name" length="50" not-null="false" />
	</class>
</hibernate-mapping>

5 POJO类Person.java

package edu.dlut.nihao.lvhl.domain;

public class Person {
	private Long id;
	private String name;

	public Long getId() {
		return id;
	}

	public void setId(Long id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}

6 数据访问DAO定义，包括两个组件IPersonDAO和实现类PersonDAO

IPeronDAO.java源码

package edu.dlut.nihao.lvhl.domain;

public interface IPersonDAO {
	void insertPerson(Object person);

	void remove(Object person);
}

Person.DAO源码

package edu.dlut.nihao.lvhl.domain;

import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

public class PersonDAO extends HibernateDaoSupport implements IPersonDAO {

	public void insertPerson(Object person) {
		getHibernateTemplate().save(person);
	}

	public void remove(Object person) {

		getHibernateTemplate().delete(person);
	}
}

7 跨库事务拦截的方法，由以DS为后缀的类实现。

IPersonDS.java源码

package edu.dlut.nihao.lvhl.domain;

public interface IPersonDS {
	void transferPerson(Person person) throws Exception;
}

PersonDS.java源码，其中transferPerson方法中有ExceptionUtil.exceptionOccur();用于产生异常

package edu.dlut.nihao.lvhl.domain;

public class PersonDS implements IPersonDS {
	private IPersonDAO localDAO;
	private IPersonDAO foreignDAO;

	public void transferPerson(Person person) throws Exception {
		localDAO.remove(person);
		foreignDAO.insertPerson(person);
//		ExceptionUtil.exceptionOccur();
	}

	public IPersonDAO getLocalDAO() {
		return localDAO;
	}

	public void setLocalDAO(IPersonDAO localDAO) {
		this.localDAO = localDAO;
	}

	public IPersonDAO getForeignDAO() {
		return foreignDAO;
	}

	public void setForeignDAO(IPersonDAO foreignDAO) {
		this.foreignDAO = foreignDAO;
	}

}

ExceptionUtil.java源码

package edu.dlut.nihao.lvhl.domain;

public final class ExceptionUtil {
	public static void exceptionOccur() {
		int[] arr = new int[1];
		arr[1] = 0;
	}
}

8 测试代码

package edu.dlut.nihao.lvhl.domain;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class ContextFactory {
	static ApplicationContext ctx = null;
	static String PERSON_NAME = "nihao";
	static long PERSON_ID = 12;

	public static Object findService(String beanId) {

		if (ctx == null) {
			ctx = new ClassPathXmlApplicationContext(
					new String[] { "applicationContext-db.xml" });
		}

		return ctx.getBean(beanId);
	}

	public static void main(String[] args) {

		IPersonDAO localDao = (IPersonDAO) ContextFactory
				.findService("local_personDAO");

		Person person = new Person();
		person.setName(PERSON_NAME);
		person.setId(PERSON_ID);

		localDao.insertPerson(person);

		// 测试跨库事务
		IPersonDS personDS = (IPersonDS) ContextFactory.findService("personDS");
		try {
			personDS.transferPerson(person);
		} catch (Exception e) {
			e.printStackTrace();
		}

	}
}