hibernate教程笔记7

阶段性总结

hibernate开发的三种方式中，
domain.object+映射文件自动创建对应的数据库
需要手动配置hibernate.cfg.xml
<property name="hbm2ddl.auto>create
有四个配置项 create update create-drop validate
create:
update:
create-drop
validate:

<property name="hbm2ddl.auto">create</property>

HibernateUtil.openSession();加载hibernate.cfg.xml文件就会自动创建，会覆原来已存在的数据

<property name="hbm2ddl.auto">update</property>

如果没表则创建，如果表已存在，则更新，若字段名变更则增加字段而不是覆盖原来的字段
字段类型变化则覆盖。

<property name="hbm2ddl.auto">create-drop</property>

在显示sessionFactory时，把已存在的数据清空。

<property name="hbm2ddl.auto">validate</property>

在开发测试过程中，配置哪个都行，项目发布后不应改动。

domain对象的细节问题。

1.默认的无参构造方法
2.无意义的id标示符
3.属性有get、set方法
4.hibernate更关心的是对象关系映射文件，但domain中不存在属性的话会报错。

hibernate.hbm.xml 有些属性是可选的，若不配置，会采用默认配置。比如表名、属性类型。但建议还是写上。

1.初始化代码

Configuration cfg=new Configuration();
cfg.configure().("hibernate.cfg.xml");
SessionFactory sessionFactory=cfg.buildSessioinFactory();

2.模板代码

Session session=null;Transaction tx=null;try {session=HibernateUtil.getCurrentSession();tx=session.beginTransaction();tx.commit();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();if(tx!=null){tx.rollback();}throw new RuntimeException(e.getMessage());}finally{if(session!=null && session.isOpen()){session.close();}}

hibernate对象的三种状态

transient 瞬时态
数据库中没有数据与之对应，超过作用于会被JVM垃圾回收器回收，一般是new出来且与session没有关联的对象。
persistent 持久态
数据库中有数据与之对应，当前与session有关联，且相关联的session没有关闭，事务没有提交，持久对象状态发生改变，在事务提交时会影响到数据库能否被hibernate检测到。
detached 游离态
数据库中有数据与之对应，但当前没有session与之关联；脱管对象状态发生改变，hibernate不能检测到。

如何判断一个对象所处状态。

看session是否处于session，看数据库中是否有对应记录

package com.qq.view;
import com.qq.util.*;
import com.qq.domain.*;
import org.hibernate.Session;
import org.hibernate.Transaction;
import java.util.List;
import java.util.Iterator;
import java.util.Set;
import org.hibernate.Query;
public class TestMain {private static Session session=null;private static Transaction ts=null;public static void main(String[] args){//hibernate对象的三种状态Course c1=new Course();  //c1就是transientc1.setCid(8L);c1.setCcredit(3L);c1.setCname("Java程序设计");Session session=null;Transaction tx=null;try {session=HibernateUtil.getCurrentSession();tx=session.beginTransaction();session.save(c1);         System.out.println(c1.getCname()); //c1处于session管理下，同时c1被保存到数据库中，因此处于persistenttx.commit();//提交后会自动关闭session//c1被保存到数据库中，但不处于session管理下，处于detached状态System.out.println(c1.getCname());} catch (Exception e) {// TODO: handle exceptione.printStackTrace();if(tx!=null){tx.rollback();new RuntimeException(e.getMessage());}}finally{if(session!=null && session.isOpen()){session.close();}}}}

many-to-one 问题
从domain入手，纯粹面向对象，通过hbm.xml建立数据库

<?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"><!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration><session-factory><property name="connection.username">scott</property><property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orcl</property><property name="dialect">org.hibernate.dialect.Oracle9Dialect</property><property name="connection.password">tiger</property><property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property><property name="show_sql">true</property><!-- 配置 自动创建关系模型 --><property name="hbm2ddl.auto">update</property><mapping resource="com/qq/domain/Department.hbm.xml" /><mapping resource="com/qq/domain/Student.hbm.xml" /></session-factory></hibernate-configuration>

package com.qq.domain;public class Department implements java.io.Serializable{private static final long serialVersionUID=1L;private Integer id;private String name;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}
}```xml
<?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">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.qq.domain"><class name="Department"><id name="id" type="java.lang.Integer"><generator class="sequence"><param name="sequence">dept_seq</param></generator></id><property name="name" type="java.lang.String"><column name="name" length="64" not-null="true"/></property></class>
</hibernate-mapping>

package com.qq.domain;public class Student implements java.io.Serializable{private static final long serialVersionUID=1L;private Integer id;private String name;private Department dept;public Department getDept() {return dept;}public void setDept(Department dept) {this.dept = dept;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}}


<?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">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping><class name="Student"><id name="id" type="java.lang.Integer"><generator class="sequence"><param name="sequence">stu_seq</param></generator></id><property name="name" type="java.lang.String"><column name="name" length="64"/></property><!-- 对于private Department dept就不能用property来配置了 将来自动生成的外键名dept_id--><many-to-one name="dept" column="dept_id"/></class>
</hibernate-mapping>

package com.qq.util;
import java.util.List;import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
final public class HibernateUtil {private static SessionFactory sessionFactory=null;//使用线程局部模式private static ThreadLocal<Session> threadLocal=new ThreadLocal<Session>();private HibernateUtil(){};static {sessionFactory=new Configuration().configure().buildSessionFactory();}//获取全新的全新的sesessionpublic static Session openSession(){return sessionFactory.openSession();}//获取和线程关联的sessionpublic static Session getCurrentSession(){Session session=threadLocal.get();//判断是否得到if(session==null){session=sessionFactory.openSession();//把session对象设置到 threadLocal,相当于该session已经和线程绑定threadLocal.set(session);}return session;}public static void closeCurrentSession(){Session s=getCurrentSession();if(s!=null&& s.isOpen() ){s.close();threadLocal.set(null);}}//这里提供一个根据id返回对象的方法public static Object findById(Class clazz,java.io.Serializable id){Session s=null;Transaction tx=null;Object obj=null;try {s=openSession();tx=s.beginTransaction();obj=s.load(clazz, id);tx.commit();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return obj;}//统一的一个修改和删除(批量 hql) hql"delete upate ...??"public static void executeUpdate(String hql,String [] parameters){Session s=null;Transaction tx=null;try {s=openSession();tx=s.beginTransaction();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.executeUpdate();tx.commit();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}}//如果要配置openSessionInView//统一的一个修改和删除(批量 hql) hql"delete upate ...??"public static void executeUpdateOpenInView(String hql,String [] parameters){Session s=getCurrentSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.executeUpdate();}//统一的添加的方法public  static void save(Object obj){Session s=null;Transaction tx=null;try {s=openSession();tx=s.beginTransaction();s.save(obj);tx.commit();} catch (Exception e) {if(tx!=null){tx.rollback();}throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null && s.isOpen()){s.close();}}}//提供一个统一的查询方法(带分页) hql 形式 from 类  where 条件=? ..public static List executeQueryByPage(String hql,String [] parameters,int pageSize,int pageNow){Session s=null;List list=null;try {s=openSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.setFirstResult((pageNow-1)*pageSize).setMaxResults(pageSize);list=query.list();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return list;}//提供一个统一的查询方法 hql 形式 from 类  where 条件=? ..public static List executeQuery(String hql,String [] parameters){Session s=null;List list=null;try {s=openSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}list=query.list();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return list;}}

package com.qq.view;
import com.qq.util.*;
import com.qq.domain.*;
import org.hibernate.Session;
import org.hibernate.Transaction;
import java.util.List;
import java.util.Iterator;
import java.util.Set;
import org.hibernate.Query;
public class TestMain {private static Session session=null;private static Transaction ts=null;public static void main(String[] args){//通过获取一个session加载cfg来创建数据库//HibernateUtil.openSession();Session s=null;Transaction tx=null;try {//使用基础模板演示s=HibernateUtil.getCurrentSession();tx=s.beginTransaction();//添加一个学生和一个部门，且把学生指定到该部门Student stu1=new Student();stu1.setName("孙仲谋");Student stu2=new Student();stu2.setName("孙策");Department d1=new Department();d1.setName("国防部");Department d2=new Department();d2.setName("财政部");stu1.setDept(d1);stu2.setDept(d2);//如果先保存学生会怎么样？ //也会成功，hibernate优化了，它先把外键置空，再保存department但建议先保存主对象，再保存从对象s.save(d1);s.save(stu1);s.save(d2);s.save(stu2);tx.commit();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();if(tx!=null){tx.rollback();}}finally{if(s!=null && s.isOpen()){s.close();}}}}

懒加载问题

什么是懒加载？
当我们查询一个对象时，在默认情况下，返回的只是该对象的普通属性，当用户使用对象属性时，才会向数据库发出再次查询

解决办法。
①Hibernate.initialize
//显示初始代理对象

Hibernate.initialize(stu3.getDept());

②修改对象关系映射文件 Department.hbm.xml <class name="Department" lazy="false">
③通过过滤器（web项目）openSessionInview

package com.qq.view;
import com.qq.util.*;
import com.qq.domain.*;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.Hibernate;
public class TestMain {private static Session session=null;private static Transaction ts=null;public static void main(String[] args){Student stu3=getStudent();System.out.println(stu3.getName()+" 学生所在部门:"+stu3.getDept().getName());}//获取某个学生public static Student getStudent() {//通过获取一个session加载cfg来创建数据库//HibernateUtil.openSession();Student stu3=null;Session s=null;Transaction tx=null;try {//使用基础模板演示s=HibernateUtil.getCurrentSession();tx=s.beginTransaction();//查询3号学生stu3=(Student)s.get(Student.class, 3);//    System.out.println(stu3.getName()+" 学生所在部门:"+stu3.getDept().getName());//显示初始代理对象// Hibernate.initialize(stu3.getDept());tx.commit();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();if(tx!=null){tx.rollback();}}finally{if(s!=null && s.isOpen()){s.close();}}return stu3;}}

one to many问题

通过一个部分号获取该部门的所有学生。

<?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"><!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration><session-factory><property name="connection.username">scott</property><property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orcl</property><property name="dialect">org.hibernate.dialect.Oracle9Dialect</property><property name="connection.password">tiger</property><property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property><property name="show_sql">true</property><!-- 配置 自动创建关系模型 --><property name="hbm2ddl.auto">update</property><mapping resource="com/qq/domain/Department.hbm.xml" /><mapping resource="com/qq/domain/Student.hbm.xml" /></session-factory></hibernate-configuration>

package com.qq.domain;public class Student implements java.io.Serializable{private static final long serialVersionUID=1L;private Integer id;private String name;private Department dept;public Department getDept() {return dept;}public void setDept(Department dept) {this.dept = dept;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}}


```xml
<?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">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.qq.domain"><class name="Student"><id name="id" type="java.lang.Integer"><generator class="sequence"><param name="sequence">stu_seq</param></generator> </id><property name="name" type="java.lang.String"><column name="name" length="64"/></property><!-- 对于private Department dept就不能用property来配置了 将来自动生成的外键名dept_id--><many-to-one name="dept" column="dept_id"/></class>
</hibernate-mapping>

package com.qq.domain;
import java.util.Set;
public class Department implements java.io.Serializable{private static final long serialVersionUID=1L;private Integer id;private String name;private Set<Student> stus;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Set<Student> getStus() {return stus;}public void setStus(Set<Student> stus) {this.stus = stus;}
}

<?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">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.qq.domain"><class name="Department"><id name="id" type="java.lang.Integer"><generator class="sequence"><param name="sequence">dept_seq</param></generator></id><property name="name" type="java.lang.String"><column name="name" length="64" not-null="true"/></property><!-- 配置one to many关系 stus是Department.java中的属性名称，Student是类名--><set name="stus" cascade="save-update"><!-- 指定Student类对应的外键 dept_id是Student.hbm.xml中指定的外键名称--><key column="dept_id"/><one-to-many class="Student"/></set></class>
</hibernate-mapping>

package com.qq.util;
import java.util.List;import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
final public class HibernateUtil {private static SessionFactory sessionFactory=null;//使用线程局部模式private static ThreadLocal<Session> threadLocal=new ThreadLocal<Session>();private HibernateUtil(){};static {sessionFactory=new Configuration().configure().buildSessionFactory();}//获取全新的全新的sesessionpublic static Session openSession(){return sessionFactory.openSession();}//获取和线程关联的sessionpublic static Session getCurrentSession(){Session session=threadLocal.get();//判断是否得到if(session==null){session=sessionFactory.openSession();//把session对象设置到 threadLocal,相当于该session已经和线程绑定threadLocal.set(session);}return session;}public static void closeCurrentSession(){Session s=getCurrentSession();if(s!=null&& s.isOpen() ){s.close();threadLocal.set(null);}}//这里提供一个根据id返回对象的方法public static Object findById(Class clazz,java.io.Serializable id){Session s=null;Transaction tx=null;Object obj=null;try {s=openSession();tx=s.beginTransaction();obj=s.load(clazz, id);tx.commit();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return obj;}//统一的一个修改和删除(批量 hql) hql"delete upate ...??"public static void executeUpdate(String hql,String [] parameters){Session s=null;Transaction tx=null;try {s=openSession();tx=s.beginTransaction();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.executeUpdate();tx.commit();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}}//如果要配置openSessionInView//统一的一个修改和删除(批量 hql) hql"delete upate ...??"public static void executeUpdateOpenInView(String hql,String [] parameters){Session s=getCurrentSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.executeUpdate();}//统一的添加的方法public  static void save(Object obj){Session s=null;Transaction tx=null;try {s=openSession();tx=s.beginTransaction();s.save(obj);tx.commit();} catch (Exception e) {if(tx!=null){tx.rollback();}throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null && s.isOpen()){s.close();}}}//提供一个统一的查询方法(带分页) hql 形式 from 类  where 条件=? ..public static List executeQueryByPage(String hql,String [] parameters,int pageSize,int pageNow){Session s=null;List list=null;try {s=openSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.setFirstResult((pageNow-1)*pageSize).setMaxResults(pageSize);list=query.list();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return list;}//提供一个统一的查询方法 hql 形式 from 类  where 条件=? ..public static List executeQuery(String hql,String [] parameters){Session s=null;List list=null;try {s=openSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}list=query.list();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return list;}}


package com.qq.view;
import com.qq.util.*;
import com.qq.domain.*;import org.hibernate.Session;
import org.hibernate.Transaction;import java.util.HashSet;
import java.util.List;
import java.util.Iterator;
import java.util.Set;
import org.hibernate.Query;
public class TestMain {private static Session session=null;private static Transaction ts=null;public static void main(String[] args){Session session=null;Transaction tx=null;try {//获取一个session加载hibernate.cfg.xml创建数据库//HibernateUtil.openSession();session=HibernateUtil.getCurrentSession();tx=session.beginTransaction();//法1//String hql="from Student where dept.id=1";//法2Department department=(Department)session.get(Department.class, 3);Set<Student> stus=department.getStus();for(Student ss:stus){System.out.println(ss.getName());}//添加学生Department d1=new Department();d1.setName("农业部");Student stu1=new Student();stu1.setName("元谋人");Student stu2=new Student();stu2.setName("张苞");Set sets=new HashSet<Student>();sets.add(stu1);sets.add(stu2);d1.setStus(sets);session.save(d1);tx.commit();//提交后会自动关闭session} catch (Exception e) {// TODO: handle exceptione.printStackTrace();if(tx!=null){tx.rollback();new RuntimeException(e.getMessage());}}finally{if(session!=null && session.isOpen()){session.close();}}}}

one to one 问题

基于主键的one to one

基于外键的one to one

<?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"><!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration><session-factory><property name="connection.username">scott</property><property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orcl</property><property name="dialect">org.hibernate.dialect.Oracle9Dialect</property><property name="connection.password">tiger</property><property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property><property name="show_sql">true</property><!-- 配置 自动创建关系模型 --><property name="hbm2ddl.auto">update</property><mapping resource="com/qq/domain/Person.hbm.xml" /><mapping resource="com/qq/domain/IdCard.hbm.xml" /></session-factory></hibernate-configuration>

package com.qq.domain;public class Person implements java.io.Serializable{private Integer id;private String name;private IdCard idCard;private static final long serialVersionUID=1L;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public IdCard getIdCard() {return idCard;}public void setIdCard(IdCard idCard) {this.idCard = idCard;}public String getName() {return name;}public void setName(String name) {this.name = name;}
}

<?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">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.qq.domain"><class name="Person"><id name="id" type="java.lang.Integer"><generator class="assigned"/></id><property name="name" type="java.lang.String"><column name="name" length="64" not-null="true"/></property><!-- 配置person和idCard属性的one to one 关系--><one-to-one name="idCard"/></class>
</hibernate-mapping>

package com.qq.domain;
import java.util.Date;
public class IdCard implements java.io.Serializable{private static final long serialVersionUID=1L;private Integer id;private Date vaildDate;private Person person;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public Person getPerson() {return person;}public void setPerson(Person person) {this.person = person;}public Date getVaildDate() {return vaildDate;}public void setVaildDate(Date vaildDate) {this.vaildDate = vaildDate;}
}

<?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">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.qq.domain"><class name="IdCard"><!-- one to one，so使用外键生成策略 <id name="id" type="java.lang.Integer"><generator class="foreign"><param name="property">person</param></generator> </id>--><!-- 基于外键的one-to-one --><id name="id" type="java.lang.Integer"><generator class="assigned"></generator></id><property name="vaildDate" type="java.util.Date"><column name="vaildDate"/></property><!-- 配置one to one <one-to-one name="person" constrained="true"/>--><many-to-one name="person" unique="true"/></class>
</hibernate-mapping>

package com.qq.view;
import com.qq.util.*;
import com.qq.domain.*;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.Transaction;public class TestMain {private static Session session=null;private static Transaction ts=null;public static void main(String[] args){Session session=null;Transaction tx=null;try {//获取一个session加载hibernate.cfg.xml创建数据库//HibernateUtil.openSession();session=HibernateUtil.getCurrentSession();tx=session.beginTransaction();//one to one 关系演示Person p1=new Person();p1.setId(16030226);p1.setName("乐进");IdCard id1=new IdCard();id1.setId(5464666);id1.setVaildDate(new Date());id1.setPerson(p1);//表示id1对象属于p1对象session.save(p1);session.save(id1);tx.commit();//提交后会自动关闭session} catch (Exception e) {// TODO: handle exceptione.printStackTrace();if(tx!=null){tx.rollback();new RuntimeException(e.getMessage());}}finally{if(session!=null && session.isOpen()){session.close();}}}}

package com.qq.util;
import java.util.List;import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
final public class HibernateUtil {private static SessionFactory sessionFactory=null;//使用线程局部模式private static ThreadLocal<Session> threadLocal=new ThreadLocal<Session>();private HibernateUtil(){};static {sessionFactory=new Configuration().configure().buildSessionFactory();}//获取全新的全新的sesessionpublic static Session openSession(){return sessionFactory.openSession();}//获取和线程关联的sessionpublic static Session getCurrentSession(){Session session=threadLocal.get();//判断是否得到if(session==null){session=sessionFactory.openSession();//把session对象设置到 threadLocal,相当于该session已经和线程绑定threadLocal.set(session);}return session;}public static void closeCurrentSession(){Session s=getCurrentSession();if(s!=null&& s.isOpen() ){s.close();threadLocal.set(null);}}//这里提供一个根据id返回对象的方法public static Object findById(Class clazz,java.io.Serializable id){Session s=null;Transaction tx=null;Object obj=null;try {s=openSession();tx=s.beginTransaction();obj=s.load(clazz, id);tx.commit();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return obj;}//统一的一个修改和删除(批量 hql) hql"delete upate ...??"public static void executeUpdate(String hql,String [] parameters){Session s=null;Transaction tx=null;try {s=openSession();tx=s.beginTransaction();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.executeUpdate();tx.commit();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}}//如果要配置openSessionInView//统一的一个修改和删除(批量 hql) hql"delete upate ...??"public static void executeUpdateOpenInView(String hql,String [] parameters){Session s=getCurrentSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.executeUpdate();}//统一的添加的方法public  static void save(Object obj){Session s=null;Transaction tx=null;try {s=openSession();tx=s.beginTransaction();s.save(obj);tx.commit();} catch (Exception e) {if(tx!=null){tx.rollback();}throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null && s.isOpen()){s.close();}}}//提供一个统一的查询方法(带分页) hql 形式 from 类  where 条件=? ..public static List executeQueryByPage(String hql,String [] parameters,int pageSize,int pageNow){Session s=null;List list=null;try {s=openSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.setFirstResult((pageNow-1)*pageSize).setMaxResults(pageSize);list=query.list();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return list;}//提供一个统一的查询方法 hql 形式 from 类  where 条件=? ..public static List executeQuery(String hql,String [] parameters){Session s=null;List list=null;try {s=openSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}list=query.list();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return list;}}

many-to-many问题

购物车-商品
qq号-qq群

<?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"><!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration><session-factory><property name="connection.username">scott</property><property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orcl</property><property name="dialect">org.hibernate.dialect.Oracle9Dialect</property><property name="connection.password">tiger</property><property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property><property name="show_sql">true</property><!-- 配置 自动创建关系模型 --><property name="hbm2ddl.auto">update</property><mapping resource="com/qq/domain/StuCourse.hbm.xml" /><mapping resource="com/qq/domain/Student.hbm.xml" /><mapping resource="com/qq/domain/Course.hbm.xml" /></session-factory></hibernate-configuration>

package com.qq.domain;
import java.util.Set;
public class Student implements java.io.Serializable{private static final long serialVersionUID=1L;private Integer id;private String name;private Set<StuCourse> stuCourses;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Set<StuCourse> getStuCourses() {return stuCourses;}public void setStuCourses(Set<StuCourse> stuCourses) {this.stuCourses = stuCourses;}}

<?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">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.qq.domain"><class name="Student"><id name="id" type="java.lang.Integer"><generator class="sequence"><param name="sequence">stu_seq</param></generator></id><property name="name" type="java.lang.String"><column name="name" length="64" not-null="true"/></property><!-- 配置student和course的关系one to many一个学生可以对应多个课程--><set name="stuCourses"><key column="student_id"/><one-to-many class="StuCourse"/></set></class>
</hibernate-mapping>

package com.qq.domain;import java.util.Set;public class Course {private Integer id;private String name;private Set<StuCourse> stuCourses;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Set<StuCourse> getStuCourses() {return stuCourses;}public void setStuCourses(Set<StuCourse> stuCourses) {this.stuCourses = stuCourses;}
}

<?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">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.qq.domain"><class name="Course"><id name="id" type="java.lang.Integer"><generator class="sequence"><param name="sequence">course_seq</param></generator></id><property name="name" type="java.lang.String"><column name="name" length="64"/></property><!-- 配置one to many 一个课程可以对应多个选课记录--><set name="stuCourses"><key column="course_id"/><one-to-many class="StuCourse"/></set></class>
</hibernate-mapping>

package com.qq.domain;public class StuCourse {private Integer id;private Integer grade;private Course course;private Student student;public Course getCourse() {return course;}public void setCourse(Course course) {this.course = course;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public Student getStudent() {return student;}public void setStudent(Student student) {this.student = student;}public Integer getGrade() {return grade;}public void setGrade(Integer grade) {this.grade = grade;}
}

<?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">
<!-- Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.qq.domain"><class name="StuCourse"><id name="id" type="java.lang.Integer"><generator class="sequence"><param name="sequence">stucourse_seq</param></generator></id><property name="grade" type="java.lang.Integer"><column name="grade" length="3"/></property><!-- 关系--><many-to-one name="course" column="course_id"/><many-to-one name="student" column="student_id"/></class>
</hibernate-mapping>

package com.qq.util;
import java.util.List;import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
final public class HibernateUtil {private static SessionFactory sessionFactory=null;//使用线程局部模式private static ThreadLocal<Session> threadLocal=new ThreadLocal<Session>();private HibernateUtil(){};static {sessionFactory=new Configuration().configure().buildSessionFactory();}//获取全新的全新的sesessionpublic static Session openSession(){return sessionFactory.openSession();}//获取和线程关联的sessionpublic static Session getCurrentSession(){Session session=threadLocal.get();//判断是否得到if(session==null){session=sessionFactory.openSession();//把session对象设置到 threadLocal,相当于该session已经和线程绑定threadLocal.set(session);}return session;}public static void closeCurrentSession(){Session s=getCurrentSession();if(s!=null&& s.isOpen() ){s.close();threadLocal.set(null);}}//这里提供一个根据id返回对象的方法public static Object findById(Class clazz,java.io.Serializable id){Session s=null;Transaction tx=null;Object obj=null;try {s=openSession();tx=s.beginTransaction();obj=s.load(clazz, id);tx.commit();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return obj;}//统一的一个修改和删除(批量 hql) hql"delete upate ...??"public static void executeUpdate(String hql,String [] parameters){Session s=null;Transaction tx=null;try {s=openSession();tx=s.beginTransaction();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.executeUpdate();tx.commit();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}}//如果要配置openSessionInView//统一的一个修改和删除(批量 hql) hql"delete upate ...??"public static void executeUpdateOpenInView(String hql,String [] parameters){Session s=getCurrentSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.executeUpdate();}//统一的添加的方法public  static void save(Object obj){Session s=null;Transaction tx=null;try {s=openSession();tx=s.beginTransaction();s.save(obj);tx.commit();} catch (Exception e) {if(tx!=null){tx.rollback();}throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null && s.isOpen()){s.close();}}}//提供一个统一的查询方法(带分页) hql 形式 from 类  where 条件=? ..public static List executeQueryByPage(String hql,String [] parameters,int pageSize,int pageNow){Session s=null;List list=null;try {s=openSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}query.setFirstResult((pageNow-1)*pageSize).setMaxResults(pageSize);list=query.list();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return list;}//提供一个统一的查询方法 hql 形式 from 类  where 条件=? ..public static List executeQuery(String hql,String [] parameters){Session s=null;List list=null;try {s=openSession();Query query=s.createQuery(hql);//先判断是否有参数要绑定if(parameters!=null&& parameters.length>0){for(int i=0;i<parameters.length;i++){query.setString(i, parameters[i]);}}list=query.list();} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());// TODO: handle exception}finally{if(s!=null&&s.isOpen()){s.close();}}return list;}}


package com.qq.view;
import com.qq.util.*;
import com.qq.domain.*;
import org.hibernate.Session;
import org.hibernate.Transaction;public class TestMain {private static Session session=null;private static Transaction ts=null;public static void main(String[] args){Session session=null;Transaction tx=null;try {//获取一个session加载hibernate.cfg.xml创建数据库//HibernateUtil.openSession();session=HibernateUtil.getCurrentSession();tx=session.beginTransaction();//添加一个学生，一门课程Student stu1=new Student();stu1.setName("星彩");Course course1=new Course();course1.setName("Java程序设计");StuCourse sc=new StuCourse();sc.setCourse(course1);sc.setStudent(stu1);sc.setGrade(88);//顺序保存session.save(stu1);session.save(course1);session.save(sc);tx.commit();//提交后会自动关闭session} catch (Exception e) {// TODO: handle exceptione.printStackTrace();if(tx!=null){tx.rollback();new RuntimeException(e.getMessage());}}finally{if(session!=null && session.isOpen()){session.close();}}}}

-- Create table
create table STUDENT
(ID   NUMBER(10) not null,NAME VARCHAR2(64 CHAR) not null
)
tablespace USERSpctfree 10initrans 1maxtrans 255storage(initial 64Kminextents 1maxextents unlimited);
-- Create/Recreate primary, unique and foreign key constraints
alter table STUDENTadd primary key (ID)using index tablespace USERSpctfree 10initrans 2maxtrans 255storage(initial 64Kminextents 1maxextents unlimited);

-- Create table
create table COURSE
(ID   NUMBER(10) not null,NAME VARCHAR2(64 CHAR)
)
tablespace USERSpctfree 10initrans 1maxtrans 255storage(initial 64Kminextents 1maxextents unlimited);
-- Create/Recreate primary, unique and foreign key constraints
alter table COURSEadd primary key (ID)using index tablespace USERSpctfree 10initrans 2maxtrans 255storage(initial 64Kminextents 1maxextents unlimited);

-- Create table
create table STUCOURSE
(ID         NUMBER(10) not null,GRADE      NUMBER(10),COURSE_ID  NUMBER(10),STUDENT_ID NUMBER(10)
)
tablespace USERSpctfree 10initrans 1maxtrans 255storage(initial 64Kminextents 1maxextents unlimited);
-- Create/Recreate primary, unique and foreign key constraints
alter table STUCOURSEadd primary key (ID)using index tablespace USERSpctfree 10initrans 2maxtrans 255storage(initial 64Kminextents 1maxextents unlimited);
alter table STUCOURSEadd constraint FKCA19334F2248A6F1 foreign key (STUDENT_ID)references STUDENT (ID);
alter table STUCOURSEadd constraint FKCA19334FFCD1D5E3 foreign key (COURSE_ID)references COURSE (ID);