package com.hibernate; 
 
import java.util.Date; 
 
public class User1 { 
 private String id; 
 private String name; 
 private String password; 
 private Date createTime; 
 private Date expireTime; 
 public String getId() { 
  return id; 
 } 
 public String getName() { 
  return name; 
 } 
 public void setName(String name) { 
  this.name = name; 
 } 
 public String getPassword() { 
  return password; 
 } 
 public void setPassword(String password) { 
  this.password = password; 
 } 
 public Date getCreateTime() { 
  return createTime; 
 } 
 public void setCreateTime(Date createTime) { 
  this.createTime = createTime; 
 } 
 public Date getExpireTime() { 
  return expireTime; 
 } 
 public void setExpireTime(Date expireTime) { 
  this.expireTime = expireTime; 
 } 
  
} 

<id name="id" type="long" column="cat_id"> 
  <generator class="org.hibernate.id.TableHiLoGenerator"> 
    <param name="table">uid_table</param> 
    <param name="column">next_hi_value_column</param> 
  </generator> 
</id> 

public class User { 
 private String name; 
 public String GetName(){ 
  return name; 
 } 
 public void SetName(String name){ 
  this.name=name; 
 } 
  
 private Group group; 
 public Group GetGroup(){ 
  return group; 
 } 
 public void SetGroup(Group group){ 
  this.group=group; 
 } 
} 

<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 
<!-- Generated 2014-5-14 23:39:25 by Hibernate Tools 3.4.0.CR1 --> 
<hibernate-mapping> 
 <class name="com.hibernate.User" table="USER"> 
  <id name="id" type="java.lang.Long"> 
   <column name="ID" /> 
   <generator class="assigned" /> 
  </id> 
   
  <!-- name的值group为User.java中的一个对应的one中的一个属性，它会自动在表中生成一列，所以使用column对列进行了重命名 --> 
  <many-to-one name="group" column="groupid"></many-to-one> 
   
 </class> 
</hibernate-mapping> 

public void testSave1(){ 
   
  Session session=null; 
  try{ 
   session=GetSession.getSession(); 
   session.beginTransaction(); 
    
   Group group=new Group(); 
   group.SetName("动力节点"); 
    
   User user1=new User(); 
   user1.SetName("张三"); 
   user1.SetGroup(group); 
    
   User user2=new User(); 
   user2.SetName("李四"); 
   user2.SetGroup(group); 
    
   session.save(user1); 
   session.save(user2); 
    
   //会报TransientObjectException错误 
   //在清理缓存时发生错误TransientObjectException 
   //因为Group为Transient状态，没有被Session，在数据库中没有匹配的数据 
   //而User为Persistent状态，在清理缓存时Hibernate在缓存中无法找到Group对象 
   //揭露：Persistent状态的对象不能引用Transient状态的对象 
   //该问题在testSave2方法中更改 
   session.getTransaction().commit(); 
  }catch(Exception e){ 
    
   e.printStackTrace(); 
   session.getTransaction().rollback(); 
  }finally{ 
   GetSession.CloseSession(session); 
  } 
 } 

public void testSave2(){ 
    
 Session session=null; 
 try{ 
  session=GetSession.getSession(); 
  session.beginTransaction(); 
   
  Group group=new Group(); 
  group.SetName("动力节点"); 
  session.save(group);  //此处将group对象设置为Persistent对象 
   
  User user1=new User(); 
  user1.SetName("张三"); 
  user1.SetGroup(group); 
   
  User user2=new User(); 
  user2.SetName("李四"); 
  user2.SetGroup(group); 
   
  session.save(user1); 
  session.save(user2); 
   
  //可以正确的保存数据 
  //因为Group和User都是Persistent状态的对象 
  //所以在Hibernate清理缓存时在session中可以找到关联对象 
  session.getTransaction().commit(); 
 }catch(Exception e){ 
   
  e.printStackTrace(); 
  session.getTransaction().rollback(); 
 }finally{ 
  GetSession.CloseSession(session); 
 } 
} 

<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 
<!-- Generated 2014-5-14 23:39:25 by Hibernate Tools 3.4.0.CR1 --> 
<hibernate-mapping> 
 <class name="com.hibernate.User" table="USER"> 
  <id name="id" type="java.lang.Long"> 
   <column name="ID" /> 
   <generator class="assigned" /> 
  </id> 
   
  <!-- 级联修改表 --> 
  <many-to-one name="group" column="groupid" cascade="save-update"></many-to-one> 
   
 </class> 
</hibernate-mapping> 

//级联cascade 
public void testSave3(){ 
  
 Session session=null; 
 try{ 
  session=GetSession.getSession(); 
  session.beginTransaction(); 
   
  Group group=new Group(); 
  group.SetName("动力节点"); 
   
  User user1=new User(); 
  user1.SetName("张三"); 
  user1.SetGroup(group); 
   
  User user2=new User(); 
  user2.SetName("李四"); 
  user2.SetGroup(group); 
   
  session.save(user1); 
  session.save(user2); 
   
  //没有抛出TransientObjectException异常 
  //因为使用了级联 
  //Hibernate会首先保存User的关联对象Group 
  //Group和User就都是Persistent状态的对象了 
  session.getTransaction().commit(); 
 }catch(Exception e){ 
  e.printStackTrace(); 
  session.getTransaction().rollback(); 
 }finally{ 
  GetSession.CloseSession(session); 
 } 
}