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。