Spring与Hibernate整合之通用Dao的实现

在上一篇文章中写了如何直接利用HibernateTemplate进行数据库操作，但在一般的项目中很少直接得到HibernateTemplate的
Bean对象从而操作数据库的，下面就简要介绍一下实现通用的数据库操作对象Dao类：

1、最基本的数据库操作接口BaseDao<T>:

 import java.io.Serializable;
 import java.util.List;

 public interface BaseDao<T> {

     Serializable save (T entity);

     void delete (T entity);
     void delete (Class<T> clazz,Serializable id);

     void update(T entity);

     T get(Class<T> clazz,Serializable id);

     List<T> findAll(Class<T> clazz);

     List<T> findAll(Class<T> clazz,String where);

 }

2、实现BaseDao<T>的实现类BaseDaoImpl<T>：

 import java.io.Serializable;
 import java.util.List;

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

 public class BaseDaoImpl<T> extends HibernateDaoSupport implements BaseDao<T>{

     @Override
     public Serializable save(T entity) {
         // TODO Auto-generated method stub
         return getHibernateTemplate().save(entity);
     }

     @Override
     public void delete(T entity) {
         // TODO Auto-generated method stub
         getHibernateTemplate().delete(entity);

     }

     @Override
     public void delete(Class clazz, Serializable id) {
         // TODO Auto-generated method stub
         delete(get(clazz,id));

     }

     @Override
     public void update(T entity) {
         // TODO Auto-generated method stub
         getHibernateTemplate().saveOrUpdate(entity);

     }

     @Override
     public T get(Class clazz, Serializable id) {
         // TODO Auto-generated method stub
         return (T) getHibernateTemplate().get(clazz, id);
     }

     @Override
     public List<T> findAll(Class clazz) {
         // TODO Auto-generated method stub
         return (List<T>) getHibernateTemplate().find("select en from "+clazz.getSimpleName()+" en");
     }

     @Override
     public List findAll(Class clazz, String where) {
         // TODO Auto-generated method stub
         return getHibernateTemplate().find("select en from "+clazz.getSimpleName()+" en where "+where);
     }

 }

3、实体User：

 import java.util.Date;

 import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
 import javax.persistence.Id;
 import javax.persistence.Temporal;
 import javax.persistence.TemporalType;

 @Entity
 public class User {

     @Id
     @Column(name="user_id")
     @GeneratedValue(strategy=GenerationType.IDENTITY)
     private Integer id;
     @Column(name="user_name")
     private String name;
     private String pass;
     @Temporal(TemporalType.DATE)
     private Date birth;

     public User() {

     }

     public User( String name, String pass, Date birth) {
         super();
         this.name = name;
         this.pass = pass;
         this.birth = birth;
     }

     public Integer getId() {
         return id;
     }

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

     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public String getPass() {
         return pass;
     }
     public void setPass(String pass) {
         this.pass = pass;
     }

     public Date getBirth() {
         return birth;
     }

     public void setBirth(Date birth) {
         this.birth = birth;
     }

 }

4、针对User类的数据库操作Dao的接口，由于继承了BaseDao<User>，基本的函数接口也不用再写了，空的接口是为了日后的扩展：

 import com.csu.comm.dao.BaseDao;
 import com.csu.domain.User;

 public interface UserDao extends BaseDao<User>{

 }

5、实现了BaseDao<User>的类UserDaoImpl，也因为继承了BaseDaoImpl<User>，基本的操作已经都实现了，空体也是为了日后的扩展：

 import java.io.Serializable;
 import java.util.List;

 import com.csu.comm.dao.BaseDaoImpl;
 import com.csu.dao.UserDao;
 import com.csu.domain.User;

 public class UserDaoImpl extends BaseDaoImpl<User> implements UserDao {

 }

6、c3p0数据库连接池所需要的数据库配置信息，放置在jdbc.properties文件中，这样也方便日后修改只需要改动属性文件，
而不需要改动配置文件：

 user=root
 password=7890
 driverClass=com.mysql.jdbc.Driver
 jdbcUrl=jdbc:mysql://localhost:3306/spring
 maxPoolSize=200
 minPoolSize=2
 initialPoolSize=2

7、hibernate配置文件hibernate.cfg.xml：

 <?xml version='1.0' encoding='utf-8'?>
 <!DOCTYPE hibernate-configuration PUBLIC
         "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
         "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

 <hibernate-configuration>

     <session-factory>
         <!-- hibernate 所需的配置信息 -->
         <property name="show_sql">true</property>
         <property name="dialect">org.hibernate.dialect.MySQLDialect</property><!--方言-->
         <property name="format_sql">true</property>
         <property name="hbm2ddl.auto">update</property>

         <!-- hibernate 指定映射类 -->
         <mapping class="com.csu.domain.User"/>

     </session-factory>

 </hibernate-configuration>

8、spring的配置文件：

 <?xml version="1.0" encoding="UTF-8"?>

 <!-- 整个Spring 文件的根元素就是beans -->
 <beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:p="http://www.springframework.org/schema/p"
 xmlns:util="http://www.springframework.org/schema/util"
 xmlns:context="http://www.springframework.org/schema/context"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd

         http://www.springframework.org/schema/util
         http://www.springframework.org/schema/util/spring-util.xsd

         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context.xsd
         ">

        <!-- *****************配置数据源*********************** -->

        <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">

            <property name="locations">
                <!-- 列出需要读取的属性文件 -->
                <list>
                    <value>classpath:jdbc.properties</value>
                </list>
            </property>

        </bean>

        <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
            p:user="${user}"
            p:password="${password}"
            p:driverClass="${driverClass}"
            p:jdbcUrl="${jdbcUrl}"
            p:maxPoolSize="${maxPoolSize}"
            p:minPoolSize="${minPoolSize}"
            p:initialPoolSize="${initialPoolSize}"
        />
        <!-- *****************配置数据源*********************** -->

     <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"
     p:dataSource-ref="dataSource"
     p:configLocation="classpath:hibernate.cfg.xml"
     />

     <!--因为UserDaoImpl继承了BaseDaoImpl<T>， BaseDaoImpl<T> 继承了 HibernateDaoSupport，HibernateDaoSupport有setSessionFactory函数-->
     <bean id="userDao" class="com.csu.dao.impl.UserDaoImpl"
         p:sessionFactory-ref="sessionFactory"

     />

 </beans>

10、测试主类：

 import java.sql.SQLException;
 import java.util.Date;
 import java.util.List;

 import org.hibernate.FlushMode;
 import org.hibernate.HibernateException;
 import org.hibernate.Session;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 import org.springframework.orm.hibernate3.HibernateCallback;
 import org.springframework.orm.hibernate3.HibernateTemplate;

 import com.csu.dao.UserDao;
 import com.csu.domain.User;

 public class SpHiTest {

     public static void main(String[] args) {
         ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");

         UserDao userDao = ctx.getBean("userDao",UserDao.class);
         List<User> users = userDao.findAll(User.class);
         for(Object u : users){
             System.out.println(((User) u).getName());
         }

     }
 }

11、结果;