【spring框架】spring之HibernateTemplate

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    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。

  • 阿里云国际版折扣https://www.yundadi.com

  • 阿里云国际,腾讯云国际,低至75折。AWS 93折 免费开户实名账号 代冲值 优惠多多 微信号:monov8 飞机:@monov6
    标签: Spring