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();