Spring中编程式事务处理(使用TransactionTemplate)

Spring的编程式事务处理，需要使用Hibernate事务回调接口，事务回调接口可以管理Hibernate的事务：

TransactionCallbackWithoutResult —— 执行事务没有返回值，例如save、update、delete等等；

TransactionCallback —— 执行事务处理后有返回值，如find要返回结果集(List)；

使用Spring的IoC容器来管理bean，具体注入的过程为：

装配DataSource —— 将DataSource注入到SessionFactory Bean中 ——
将SessionFactory Bean注入到HibernateTransactionManager中 —— 将SessionFactory
Bean与HibernateTransactionManager Bean一起都注入到DAO中

对应的Spring的配置文件applicationContext.xml的配置如下所示：

<?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="threeDataSource
"

   class="org.springframework.jdbc.datasource.DriverManagerDataSource">

   <property name="driverClassName"

    value="com.microsoft.jdbc.sqlserver.SQLServerDriver">

   </property>

   <property name="url"

    value="jdbc:microsoft:sqlserver://localhost:1433;databasename=hibernate">

   </property>

   <property name="username" value="sa"></property>

   <property name="password" value="111111"></property>

</bean>

<bean id="threeSessionFactory
"

   class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">

   <property name="dataSource">

    <ref bean="threeDataSource
" />

   </property>

   <property name="mappingResources">

    <list>

     <value>org/shirdrn/entity/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="hTransactionManager
"

   class="org.springframework.orm.hibernate3.HibernateTransactionManager"

   abstract="false" singleton="true" lazy-init="default"

   autowire="default" dependency-check="default">

   <property name="sessionFactory">

    <ref bean="threeSessionFactory
" />

   </property>

</bean>

<bean id="threePersonDao" class="org.shirdrn.no.three.dao.PersonDao"

   abstract="false" singleton="true" lazy-init="default"

   autowire="default" dependency-check="default">

   <property name="transactionManager">

    <ref bean="hTransactionManager
"/>

   </property>

   <property name="sessionFactory">

    <ref bean="threeSessionFactory
" />

   </property>

</bean>

</beans>

实体类Person对应DAO的服务接口为IPerson，如下所示：

package org.shirdrn.no.three.interf;

import java.util.List;

import org.shirdrn.entity.Person;

public interface IPersonDao {

public void createPerson(Person person);

public void updatePerson(Person person);

public void deletePerson(Person person);

public List queryPerson(String hql);

public Person queryOnePerson(String hql);

}

PersonDao实现了服务接口IPerson，同时必须集成HibernateDaoSupport，因为在
HibernateDaoSupport中实现了DataSource、SessionFactory的setter方法，继承
HibernateDaoSupport从而将SessionFactory注入到DAO中可以简化编程。

PersonDao的实现如下所示：

package org.shirdrn.no.three.dao;

import java.util.List;

import org.shirdrn.entity.Person;

import org.shirdrn.no.three.interf.IPersonDao;

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

import org.springframework.transaction.PlatformTransactionManager;

import org.springframework.transaction.TransactionDefinition;

import org.springframework.transaction.TransactionStatus;

import org.springframework.transaction.support.TransactionCallback;

import org.springframework.transaction.support.TransactionCallbackWithoutResult;

import org.springframework.transaction.support.TransactionTemplate;

public class PersonDao extends HibernateDaoSupport implements IPersonDao{

private TransactionTemplate transactionTemplate;

public void setTransactionManager(PlatformTransactionManager transactionManager){     // 注入TransactionManager

   this.transactionTemplate = new TransactionTemplate(transactionManager);     //   以注入的TransactionManager作为参数，获取一个TransactionTemplate实例，该实例封装了Hibernate的行为

}

public void createPerson(final Person person) {

   transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);

   transactionTemplate.execute(new TransactionCallbackWithoutResult(){    // 使用无返回值的事务回调接口

    @Override

    protected void doInTransactionWithoutResult(TransactionStatus arg0) {

     getHibernateTemplate().save(person);    

    }   

   });

}

public void deletePerson(final Person person) {

   transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);

   transactionTemplate.execute(new TransactionCallbackWithoutResult(){     // 使用无返回值的事务回调接口

    @Override

    protected void doInTransactionWithoutResult(TransactionStatus arg0) {

     getHibernateTemplate().delete(person);    

    }   

   });

}

public void updatePerson(final Person person) {

   transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);

   transactionTemplate.execute(new TransactionCallbackWithoutResult(){     // 使用无返回值的事务回调接口

    @Override

    protected void doInTransactionWithoutResult(TransactionStatus arg0) {

     getHibernateTemplate().update(person);    

    }   

   });

}

public List queryPerson(final String hql) {

   transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);

   List list = (List)transactionTemplate.execute(new TransactionCallback(){   // 使用带返回值的事务回调接口

    public Object doInTransaction(TransactionStatus arg0) {

     System.out.println(hql);

     return getHibernateTemplate().find(hql);

    }   

   });

   return list;

}

public Person queryOnePerson(final String hql) {

   transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);

   return (Person)transactionTemplate.execute(new TransactionCallback(){     // 使用带返回值的事务回调接口

    public Object doInTransaction(TransactionStatus arg0) {

     return getHibernateTemplate().find(hql).get(0);

    }   

   });

}

}

编写测试函数，如下所示：

package org.shirdrn.no.three.test;

import org.shirdrn.entity.Person;

import org.shirdrn.no.three.interf.IPersonDao;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringTest {

public static void main(String[] args) {

   ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");

   IPersonDao personDao = (IPersonDao)ctx.getBean("threePersonDao");
   /**

   * 测试save

   */

   /*Person p = new Person();

   p.setId("200804150016");

   p.setName("Sujnn");

   p.setAddr("Shanghai");

   p.setAge(new Integer(22));

   p.setGender("male");

   personDao.createPerson(p);*/
   /**

   * 测试update

   */

   /*Person p = new Person();

   p.setId("200804150016");

   p.setName("SujnnXXX");

   p.setAddr("Hongkong");

   p.setAge(new Integer(22));

   p.setGender("male");

   personDao.updatePerson(p);*/
   /**

   * 测试delete

   */

   /*Person p = new Person();

   p.setId("200804150016");

   personDao.deletePerson(p);*/
   /**

   * 测试find(HQL)

   */

   /*List list = personDao.queryPerson("from Person");

   for(Object o : list.toArray()){

    Person p = (Person)o;

    System.out.println("Id   = "+p.getId());

    System.out.println("Name = "+p.getName());

    System.out.println("Addr = "+p.getAddr());

    System.out.println("******************************");

   }*/
   /**

   * 测试find(Person)

   */

   Person p = personDao.queryOnePerson("from Person p where p.id='200804150015'");

   System.out.println("Id    = "+p.getId());

   System.out.println("Name = "+p.getName());

   System.out.println("Addr = "+p.getAddr());

   System.out.println("Gender= "+p.getGender());

   System.out.println("Age = "+p.getAge());

}

}

以上主函数中的五个测试均成功。