【spring框架】spring之HibernateTemplate

标签：cn 框架 spring edu springframework HibernateTemplate org import public

HibernateTemplate是spring对hibernate使用的一个简单封装:
i.设计模式Template Method模板方法
ii.Callback回调(钩子函数)

一般我们写save方法都是

public void save(User u) {
    Session s=null;
    try {
      s=sessionFactory.getCurrentSession();
      s.beginTransaction();
      s.save(u);
      s.getTransaction().commit();
    } catch (Exception e) {
      e.printStackTrace();
      s.getTransaction().rollback();
    }finally{
      if(s!=null){
        s.close();
        s=null;
      }
    }
    System.out.println("add success!!");    
  }

HibernateTemplate替我们封装了s.save(u);之前和之后的代码，交给我们一个接口，我们去填中间的事务(save等)就行了。这样写程序就会比较方便。

下面来模拟一下HibernateTemplate的封装原理，让我们更好的去理解HibernateTemplate:

MyHibernateTemplate:

package cn.edu.hpu.HibernateTemplate;

import org.hibernate.Session;

public class MyHibernateTemplate {
  public void executeWithNativeSession(MyHibernateCallback callback){
    Session s=null;
    try {
      s=getSession();
      s.beginTransaction();
      
      callback.doInHibernate(s);//这里的方法用户自己就可以在接口里去写(save什么的)
      
      s.getTransaction().commit();
    } catch (Exception e) {
      e.printStackTrace();
      s.getTransaction().rollback();
    }finally{
      if(s!=null){
        s.close();
        s=null;
      }
    }
  }
  
  public Session getSession(){
    //拿Session,这里就省略不写了
    Session session=null;
    return session;
  }
}

MyHibernateCallback.java:

package cn.edu.hpu.HibernateTemplate;

import org.hibernate.Session;

public interface MyHibernateCallback {
  public void doInHibernate(Session s); 
}

//如何去用MyHibernateTemplate方法
  public static void main(String[] args) {
    new MyHibernateTemplate().executeWithNativeSession(new MyHibernateCallback() {
      public void doInHibernate(Session s) {
        s.save(null);//或其他事务
      }
    });
  }

是不是更加理解HibernateTemplate了？

下面来看看如何使用HibernateTemplate。

实现方式：

1.第一种:(建议)

a)在spring中初始化HibernateTemplate，注入sessionFactory

b)DAO里注入HibernateTemplate

c)save写getHibernateTemplate.save()

测试:

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: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="cn.edu.hpu"/>


  <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">
        <value>classpath:com/foo/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>cn.edu.hpu.model.User</value>
          <value>cn.edu.hpu.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>
    <!-- 有关事务的配置 -->
    <bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
       <property name="sessionFactory" ref="sessionFactory"/>
  </bean>
  <!-- tx的Annotation配置 -->
  <!-- <tx:annotation-driven transaction-manager="txManager"/> -->
    <aop:config>
      <aop:pointcut expression="execution(public * cn.edu.hpu.service..*.*(..))" id="businessService"/>
      <aop:advisor pointcut-ref="businessService" advice-ref="txAdvice"/>
    </aop:config>
    <tx:advice id="txAdvice" transaction-manager="txManager">
      <tx:attributes>
         <tx:method name="get*" read-only="true"/>
           <tx:method name="add*" propagation="REQUIRED"/>
        </tx:attributes>
    </tx:advice>


    <!--hibernateTemplate的配置-->
    <bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate">
  <property name="sessionFactory" ref="sessionFactory"></property>
    </bean>
</beans>

User.java:

package cn.edu.hpu.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class User {
  private int id;
  private String name;


  @Id
  @GeneratedValue
  public int getId() {
    return id;
  }
  public void setId(int id) {
    this.id = id;
  }
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
}

UserDao.java:

package cn.edu.hpu.dao;

import org.springframework.stereotype.Component;

import cn.edu.hpu.model.User;

public interface UserDao {

  public void save(User u);
}

UserDaoImpl.java:

package cn.edu.hpu.dao.Impl;

import javax.annotation.Resource;

import org.springframework.orm.hibernate3.HibernateTemplate;
import org.springframework.stereotype.Component;

import cn.edu.hpu.dao.UserDao;
import cn.edu.hpu.model.User;

@Component("u")
public class UserDaoImpl implements UserDao{
  
  private HibernateTemplate hibernateTemplate;
  
  public HibernateTemplate getHibernateTemplate() {
    return hibernateTemplate;
  }

  @Resource(name="hibernateTemplate")
  public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {
    this.hibernateTemplate = hibernateTemplate;
  }

  public void save(User u) {
    hibernateTemplate.save(u);
    System.out.println("add success!!");    
  }
  
}

UserService.java:

package cn.edu.hpu.service;

import javax.annotation.Resource;

import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

import cn.edu.hpu.dao.LogDao;
import cn.edu.hpu.dao.UserDao;
import cn.edu.hpu.model.Log;
import cn.edu.hpu.model.User;

@Component("userService")
public class UserService {


  private UserDao userDao;
  
  public UserDao getUserDao() {
    return userDao;
  }
  
  @Resource(name="u")
  public void setUserDao(UserDao userDao) {
    this.userDao = userDao;
  }
  
  public void add(User u){
    this.userDao.save(u);
  }
}

测试方法:

UserServiceTest.java:

package cn.edu.hpu.service;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;


import cn.edu.hpu.model.User;


public class UserServiceTest {
  
  @Test
  public void testAdd() throws Exception{
    ClassPathXmlApplicationContext ctx=new ClassPathXmlApplicationContext("beans.xml");
    
    UserService userService=(UserService)ctx.getBean("userService");
    System.out.println(userService.getClass());
    User u=new User();
    u.setName("jack");
    userService.add(u);
    ctx.destroy();
  }
}

测试结果:

class cn.edu.hpu.service.UserService$$EnhancerByCGLIB$$30e9ad8d

Hibernate: insert into User (name) values (?)

add success!!

测试成功！！

2.第二种:

a)从HibernateDaoSupport继承

b)必须写在xml文件中，无法使用Annotation，因为set方法在父类中，而且是final的

例子实现:

对一个Log实体类进行save:

不用SessionFactory，也不用get和set这个HIbernateTemplate，只需要从HibernateDaoSupport继承:

package cn.edu.hpu.dao.Impl;

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

import cn.edu.hpu.dao.LogDao;
import cn.edu.hpu.model.Log;


@Component("logDao")
public class LogDaoImpl extends HibernateDaoSupport implements LogDao{


  public void save(Log log) {
    this.getHibernateTemplate().save(log);
    //或直接this.save(log);
    System.out.println("Log add success!!");    
  }
}

这里你要在beans.xml中去注入HibernateDaoSupport的SessionFactory:

<?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="cn.edu.hpu"/>
  
  <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">
        <value>classpath:com/foo/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>cn.edu.hpu.model.User</value>
          <value>cn.edu.hpu.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 id="logDao" class="cn.edu.hpu.dao.Impl.LogDaoImpl">
    <property name="sessionFactory" ref="sessionFactory"></property>
  </bean>
</beans>

测试:

package cn.edu.hpu.service;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;


import cn.edu.hpu.model.Log;


public class UserServiceTest {
  
  @Test
  public void testAdd() throws Exception{
    ClassPathXmlApplicationContext ctx=new ClassPathXmlApplicationContext("beans.xml");
    
    UserService userService=(UserService)ctx.getBean("userService");
    System.out.println(userService.getClass());
    Log log=new Log();
    userService.add(log);
    ctx.destroy();
  }
}

测试结果:

class cn.edu.hpu.service.UserService$$EnhancerByCGLIB$$31bbf2e4

Hibernate: insert into t_log (msg) values (?)

Log add success!!

个人感觉每次使用this.getHibernateTemplate()的时候还要在配置文件里一一配置，不如方法一来得痛快。

也可以用简单的办法去解决这样的问题来更好的使用方法二操纵HibernateTemplate:

单独建立一个类(假设叫Abstrect类)去get和set这个HibernateTemplate，在beans.xml配置文件中注入HibernateTemplate，所有的需要使用HibernateTemplate的类都去继承这个Abstrect类，这时候就可以使用this.getHibernateTemplate()了。就没有必要一一的在beans中配一遍了。

(这里实体类使用的是Annotation，如果全部使用的是XML，就让Abstrect类去继承HibernateDaoSupport)

能不用继承就不用继承，HibernateDaoSupport的使用不太重要，尽量使用方法一吧。

标签：cn,框架,spring,edu,springframework,HibernateTemplate,org,import,public
From： https://blog.51cto.com/u_16012040/6131093

【spring框架】spring之HibernateTemplate

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