Hibernate annotations 入门

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首先确保你的classpath中加入了 hibernate-annotations.jar ejb3-persistence.jar hibernate-commons-annotations.jar以及hibernate的其他jar包；

hibernate.cfg.xml 的内容：

<!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="connection.username">sa</property>
<property name="connection.url">
  jdbc:mysql://localhost:3306/db
</property>
<property name="dialect">
  org.hibernate.dialect.MySQLDialect
</property>
<property name="connection.driver_class">
  com.mysql.jdbc.Driver
</property>
  <property name="hbm2ddl.auto">create</property>
<mapping class="annotations.Flight" />

</session-factory>
</hibernate-configuration>

我们的要映射的实体类： Flight

/*
************************************************************
*本文件归属于软件有限公司，未经许可，不得擅自使用、拷贝和修改
*项目组:ESB小组
*版本: SychroESB1.0
*日期：2007-11-20
*时间：上午08:22:50
*作者：Administrator
***********************************************************
*/
package annotations;

import java.io.Serializable;

import javax.persistence.Basic;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Transient;

@Entity
public class Flight implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;

Long id;

String name;

int age;
// @Lob
//
@Transient
public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

@Basic(fetch = FetchType.LAZY)
public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

@Id @GeneratedValue(strategy=GenerationType.AUTO)

public Long getId() {
return id;
}

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

helper类： HibernateUtil

/*
************************************************************
*本文件归属于软件有限公司，未经许可，不得擅自使用、拷贝和修改
*项目组:ESB小组
*版本: SychroESB1.0
*日期：2007-11-20
*时间：上午08:31:43
*作者：Administrator
***********************************************************
*/
package annotations;

import org.hibernate.*;
import org.hibernate.cfg.*;

public class HibernateUtil {

private static final SessionFactory sessionFactory;

static {
try {

   sessionFactory = new AnnotationConfiguration().configure(
   "hibernate.cfg.xml").buildSessionFactory();

  } catch (Throwable ex) {
   // Log exception!
   throw new ExceptionInInitializerError(ex);
  }
}

public static Session getSession() throws HibernateException {
return sessionFactory.openSession();
}
}

测试类：

package annotations;

import org.hibernate.Session;
import org.hibernate.SessionFactory;

public class Main {
private static SessionFactory sessionFactory;

public static void main(String[] args) throws Exception {
long st = System.currentTimeMillis();

Session s = HibernateUtil.getSession();

s.beginTransaction();

  Flight f=new Flight();

  f.setId(new Long(100));
  f.setName("n");
  s.save(f);












  s.flush();
  s.getTransaction().commit();

  s.close();
  long end = System.currentTimeMillis();
  System.out.println("用时： ");
  System.out.print(end - st);

}
}