Hibernate4 认识Java Project简单实用

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1.配置hibernate.cfg.xm文件,这个xml文件放到src文件下面，如下所示

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
   <session-factory>
       
       <property name="hibernate.connection.driver_class">
           com.mysql.jdbc.Driver
       </property>
       <property name="hibernate.connection.url">
           jdbc:mysql://localhost:3306/data
       </property>
       <property name="hibernate.connection.username">
           root
       </property>
       <property name="hibernate.connection.password">
           root
       </property>
       <property name="hibernate.connection.pool_size">
           1
       </property>
       <property name="show_sql">
           true
       </property>
       <property name="dialect">
           org.hibernate.dialect.MySQLDialect
       </property>
       
       <property name="hibernate.current_session_context_class">
           thread
       </property>

       
       <property name="cache.provider_class">
           org.hibernate.cache.internal.NoCacheProvider
       </property>

       
       <property name="show_sql">
           true
       </property>

       
       <property name="hbm2ddl.auto">
           update
       </property>
       <mapping resource="com/broadvision/hibernatefirst/Person.hbm.xml" />
   </session-factory>
</hibernate-configuration>

本例实用Mysql数据库。

hibernate.connection.url 代表数据库的url，本例中实用本地Mysql服务器中的data数据库。mapping对应xml文件把类和数据库中的表对应。

2.Person.hbm.xml 文件的配置如下

<?xml version='1.0'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.broadvision.hibernatefirst">
   <class name="Person" table="person">
       <id name="id" type="int">
             <generator class="increment" />
       </id>

       <property name="name" type="java.lang.String">
       </property>

   </class>
</hibernate-mapping>

Person.hbm.xml 文件和它对应的类Person一起放在包packagecom.broadvision.hibernatefirst 下面。

3.Person类的代码如图：

package com.broadvision.hibernatefirst;

public class Person {

   private int id;
   private String name;
   public Person() {
       super();
   }
   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;
   }

4.项目用到的的jar可以放到一个library西面，如下图

hibernate4 用到的jar在“${hibernate_home}\lib\required\*”目录下面，不要忘记连接特定数据库的jdbc的jar包。

如MySql的mysql-connector-java-5.1.3-rc-bin.jar.

5.如何得到SessionFactory来对数据库进行操作呢？下面的代码就可以了：

public class PersonDetailTest {
   private static SessionFactory sessionFactory;
   private static ServiceRegistry serviceRegistry;

   public static void main(String[] args) {
       Session session = null;
       try {
           try {

                //得到SessionFactory
               Configuration cfg = new Configuration().configure();
               serviceRegistry = new ServiceRegistryBuilder().applySettings(
                       cfg.getProperties()).buildServiceRegistry();
               sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();;

           } catch (Throwable ex) {
               System.err.println("Failed to create sessionFactory object."
                       + ex);
           }
           session = sessionFactory.openSession();

           Person person = new Person();

           //事务里增加一个Person，如果增加时候可以回滚。
           Transaction tx = session.beginTransaction();
           person.setName("Roseindia");
           session.save(person);
           tx.commit();
           System.out.println("Done");
       } catch (Exception e) {
           System.out.println(e.getMessage());
       } finally {

           //最后关闭session
           session.close();
       }
   }