Hibernate核心类和接口的详细介绍

<?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的核心配置文件 -->
<hibernate-configuration> 
 <session-factory>
 <!--配置使用的driver -->
 <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
 <property name="connection.username">root</property>
 <property name="connection.password">xu827928</property>
 <property name="connection.url">jdbc:mysql://127.0.0.1:3306/hbmtest</property>
 <!-- 配置dialect方言，明确告诉hibernate连接的是哪种数据库 -->
 <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
 <!-- 显示出对应sql语句 -->
 <property name="show_sql">true</property>
 <!-- 格式化输出sql语句 -->
 <property name="format_sql">true</property> 
 <!--让hibernate帮我们创建 一张表 -->
 <!-- 
  update:如果没有表则创建表 如果有表 则看表结构是否变化 如果有变化则会创建新表
  如果没有则添加
  create:每次都创建新的数据库
  -->
 <!-- <property name="hbm2ddl.auto">create</property> -->
 <property name="hbm2ddl.auto">update</property> 
 <!-- 指定管理对象映射文件 -->
 <mapping resource="com/lc/domain/Employee.hbm.xml"></mapping>
 </session-factory>
</hibernate-configuration>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
    '-//Hibernate/Hibernate Mapping DTD 3.0//EN'
    'http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd'>
<!-- 这是映射Employee表的hibernate -->
<!-- 该文件用于配置domain对象和表的映射关系 -->
<hibernate-mapping package="com.lc.domain">
 <class name="Employee" table="employee">
 <!-- id元素用于指定主键属性 --> 
 <id name="id" column="id" type="java.lang.Integer">
  <generator class="increment" />  
 </id>
 <!-- 对其他属性的配置 -->
 <property name="name" type="java.lang.String">
  <column name="name" not-null="false" />
 </property>
 <property name="email" type="java.lang.String">
  <column name="email" not-null="false" />
 </property>
 <property name="hiredate" type="java.util.Date">
  <column name="hiredate" not-null="false" />
 </property>
 </class>
</hibernate-mapping>

Configuration cf=new Configuration().configure();

 Configuration cf=new Configuration().configure();
 SessionFactory sf=cf.buildSessionFactory();
 Session s=sf.getCurrentSession();
 //或者是: Session s=sf.openSession();

 Configuration cf=new Configuration().configure();
 SessionFactory sf=cf.buildSessionFactory();
 Session s=sf.getCurrentSession();
 //或者是: Session s=sf.openSession();

<class name="Employee" lazy="false" table="employee">

* 如果使用的是本地事务（jdbc事务）

<property name="hibernate.current_session_context_class">thread</property>

* 如果使用的是全局事务（jta事务）

<property name="hibernate.current_session_context_class">jta</property> 

public class HibernateUtil {
 public static final ThreadLocal session =new ThreadLocal();
 public static final SessionFactory sessionFactory;
  static {
   try {
    sessionFactory = new Configuration().configure().buildSessionFactory();
   } catch (Throwable ex) {
      throw new ExceptionInInitializerError(ex);
   }   
 }
 public static Session currentSession() throws HibernateException {
    Session s = session.get();
    if(s == null) {
     s = sessionFactory.openSession();session.set(s);}
     return s;} 
  public static void closeSession() throws HibernateException {
      Session s = session.get();
    if(s != null) { s.close();}
    session.set(null); }}

Transaction ts=s.beginTransaction();
...
ts.commit();s.close()； 发生异常需要ts.rollback()回滚.

* 如果使用的是本地事务（jdbc事务）

<property name="hibernate.current_session_context_class">thread</property>

* 如果使用的是全局事务（jta事务）

<property name="hibernate.current_session_context_class">jta</property> 

Criteria crit = sess.createCriteria(Cat.class);
crit.setMaxResults(50);
List cats = crit.list();

List cats = sess.createCriteria(Cat.class)
 .add( Restrictions.like("name", "Fritz%") )
 .add( Restrictions.between("weight", minWeight, maxWeight) )
 .list();