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為User.java中的一個對應的one中的一個屬性，它會自動在表中生成一列，所以使用column對列進行了重命名 --> 
  <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("動力節(jié)點"); 
    
   User user1=new User(); 
   user1.SetName("張三"); 
   user1.SetGroup(group); 
    
   User user2=new User(); 
   user2.SetName("李四"); 
   user2.SetGroup(group); 
    
   session.save(user1); 
   session.save(user2); 
    
   //會報TransientObjectException錯誤 
   //在清理緩存時發(fā)生錯誤TransientObjectException 
   //因為Group為Transient狀態(tài)，沒有被Session，在數(shù)據(jù)庫中沒有匹配的數(shù)據(jù) 
   //而User為Persistent狀態(tài)，在清理緩存時Hibernate在緩存中無法找到Group對象 
   //揭露：Persistent狀態(tài)的對象不能引用Transient狀態(tài)的對象 
   //該問題在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("動力節(jié)點"); 
  session.save(group);  //此處將group對象設置為Persistent對象 
   
  User user1=new User(); 
  user1.SetName("張三"); 
  user1.SetGroup(group); 
   
  User user2=new User(); 
  user2.SetName("李四"); 
  user2.SetGroup(group); 
   
  session.save(user1); 
  session.save(user2); 
   
  //可以正確的保存數(shù)據(jù) 
  //因為Group和User都是Persistent狀態(tài)的對象 
  //所以在Hibernate清理緩存時在session中可以找到關聯(lián)對象 
  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> 
   
  <!-- 級聯(lián)修改表 --> 
  <many-to-one name="group" column="groupid" cascade="save-update"></many-to-one> 
   
 </class> 
</hibernate-mapping> 

//級聯(lián)cascade 
public void testSave3(){ 
  
 Session session=null; 
 try{ 
  session=GetSession.getSession(); 
  session.beginTransaction(); 
   
  Group group=new Group(); 
  group.SetName("動力節(jié)點"); 
   
  User user1=new User(); 
  user1.SetName("張三"); 
  user1.SetGroup(group); 
   
  User user2=new User(); 
  user2.SetName("李四"); 
  user2.SetGroup(group); 
   
  session.save(user1); 
  session.save(user2); 
   
  //沒有拋出TransientObjectException異常 
  //因為使用了級聯(lián) 
  //Hibernate會首先保存User的關聯(lián)對象Group 
  //Group和User就都是Persistent狀態(tài)的對象了 
  session.getTransaction().commit(); 
 }catch(Exception e){ 
  e.printStackTrace(); 
  session.getTransaction().rollback(); 
 }finally{ 
  GetSession.CloseSession(session); 
 } 
}