Hibernate 一对多 保存和修改数据

Student和Sclass表,Student外键cid是Sclass的cid

create table sclass(
cid varchar(8) primary key,
cname varchar(10)
)go
create table Student (
sid int primary key,
sname varchar(10),
sno varchar(10),
sex varchar(2),
email varchar(8),
cid varchar(8)
foreign key (cid) references sclass(cid)
)

自动生成的OMR映射文件(Myeclise逆向工程自动生成映射文件的详细步骤见上一篇Hibernate简单使用)

Sclass.hbm.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="org.rong.bean.Sclass" table="sclass" schema="dbo" catalog="XFL_XNH">
        <id name="cid" type="string">
            <column name="cid" length="8" />
            <generator class="assigned" />
        </id>
        <property name="cname" type="string">
            <column name="cname" length="10" />
        </property>
        <set name="students" inverse="true">
            <key>
                <column name="cid" length="8" />
            </key>
            <one-to-many class="org.rong.bean.Student" />
        </set>
    </class>
</hibernate-mapping>

Student.hbm.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="org.rong.bean.Student" table="Student" schema="dbo" catalog="XFL_XNH">
        <id name="sid" type="integer">
            <column name="sid" />
            <generator class="assigned" />
        </id>
        <many-to-one name="sclass" class="org.rong.bean.Sclass" fetch="select">
            <column name="cid" length="8" />
        </many-to-one>
        <property name="sname" type="string">
            <column name="sname" length="10" />
        </property>
        <property name="sno" type="string">
            <column name="sno" length="10" />
        </property>
        <property name="sex" type="string">
            <column name="sex" length="2" />
        </property>
        <property name="email" type="string">
            <column name="email" length="8" />
        </property>
    </class>
</hibernate-mapping>

HibernateSessionFactory.java为Myeclipse自动生成的SessionFactory。

package org.rong.util;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

/**
 * Configures and provides access to Hibernate sessions, tied to the
 * current thread of execution.  Follows the Thread Local Session
 * pattern, see {@link http://hibernate.org/42.html }.
 */
public class HibernateSessionFactory {

    /**
     * Location of hibernate.cfg.xml file.
     * Location should be on the classpath as Hibernate uses
     * #resourceAsStream style lookup for its configuration file.
     * The default classpath location of the hibernate config file is
     * in the default package. Use #setConfigFile() to update
     * the location of the configuration file for the current session.
     */
    private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
    private static org.hibernate.SessionFactory sessionFactory;

    private static Configuration configuration = new Configuration();
    private static ServiceRegistry serviceRegistry; 

    static {
        try {
            configuration.configure();
            serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        } catch (Exception e) {
            System.err.println("%%%% Error Creating SessionFactory %%%%");
            e.printStackTrace();
        }
    }
    private HibernateSessionFactory() {
    }

    /**
     * Returns the ThreadLocal Session instance.  Lazy initialize
     * the <code>SessionFactory</code> if needed.
     *
     *  @return Session
     *  @throws HibernateException
     */
    public static Session getSession() throws HibernateException {
        Session session = (Session) threadLocal.get();

        if (session == null || !session.isOpen()) {
            if (sessionFactory == null) {
                rebuildSessionFactory();
            }
            session = (sessionFactory != null) ? sessionFactory.openSession()
                    : null;
            threadLocal.set(session);
        }

        return session;
    }

    /**
     *  Rebuild hibernate session factory
     *
     */
    public static void rebuildSessionFactory() {
        try {
            configuration.configure();
            serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        } catch (Exception e) {
            System.err.println("%%%% Error Creating SessionFactory %%%%");
            e.printStackTrace();
        }
    }

    /**
     *  Close the single hibernate session instance.
     *
     *  @throws HibernateException
     */
    public static void closeSession() throws HibernateException {
        Session session = (Session) threadLocal.get();
        threadLocal.set(null);

        if (session != null) {
            session.close();
        }
    }

    /**
     *  return session factory
     *
     */
    public static org.hibernate.SessionFactory getSessionFactory() {
        return sessionFactory;
    }
    /**
     *  return hibernate configuration
     *
     */
    public static Configuration getConfiguration() {
        return configuration;
    }

}

创建操作类

package org.rong.test;

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;
import org.rong.bean.Sclass;
import org.rong.bean.Student;
import org.rong.util.HibernateSessionFactory;

public class Operate {
    private Session session=null;

    public Operate() {
        session=HibernateSessionFactory.getSession();
//        Transaction tran=session.beginTransaction();
//        Configuration config=new Configuration().configure();
//        SessionFactory facetory=config.buildSessionFactory();
//        this.session=facetory.openSession();
    }
    public Object get(Class clazz,String id){
        Transaction tran=this.session.beginTransaction();
        Object obj=this.session.get(clazz, id);
        tran.commit();
        return obj;
    }
    public void insert(Object obj){
        Transaction tran=this.session.beginTransaction();
        this.session.save(obj);
        tran.commit();
    }
    public void update(Object obj){
        Transaction tran=this.session.beginTransaction();
        this.session.update(obj);
        tran.commit();
    }
    public void delete(Object obj){
        Transaction tran=this.session.beginTransaction();
        this.session.delete(obj);
        tran.commit();
    }
    public List<Student> findAllStudent(){
        Transaction tran=this.session.beginTransaction();
        Query query=session.createQuery("from Student ");
//        query.setFirstResult(1);
        List<Student> students=(List<Student>)query.list();
        tran.commit();
        return students;
    }
    public List<Sclass> findAllSclass(){
        Transaction tran=this.session.beginTransaction();
        Query query=session.createQuery("from Student ");
//        query.setFirstResult(1);
        List<Sclass> sclasses=(List<Sclass>)query.list();
        tran.commit();
        return sclasses;
    }
}

测试类

package org.rong.test;

import java.util.List;

import org.rong.bean.Sclass;
import org.rong.bean.Student;

public class StudentTest {

    /**
     * @param args
     */
    public static void main(String[] args) {
//        Configuration config=new Configuration().configure();
//        SessionFactory facetory=config.buildSessionFactory();
//         Session session=facetory.openSession();
//        Session session=HibernateSessionFactory.getSession();
//        Transaction tran=session.beginTransaction();
//           Student stu=new Student();
//           stu.setId("015");
//           stu.setSname("dsfhdjdfu");
//           stu.setSno("03130498");
//           stu.setSex("男");
//           stu.setEmail("dfdw@163.com");
//           session.save(stu);
//        Query query=session.createQuery("from Student");
//        List<Student> students=(List<Student>)query.list();
//      for(Student st:students){
//        System.out.println("s:"+st.getId()+st.getSname()+st.getEmail());
//    }
//        Sclass sc=new Sclass();
//        sc.setClassname("一班");
//        session.save(sc);
        Operate op=new Operate();

//           Sclass sc=new Sclass();
//           sc.setCid("1");
//           sc.setCname("一班");
//           op.insert(sc);
           Sclass sclass=(Sclass) op.get(Sclass.class,"1");
           Student stu=new Student();
           stu.setSid(1);
           stu.setSname("王府大55");
           stu.setSex("男");
           stu.setEmail("z@3.com");
           stu.setSclass(sclass);
           op.update(stu);
           List<Student> students=op.findAllStudent();
           for(Student stu1:students){
               System.out.println(stu1.getSclass().getCid()+stu1.getSname());
           }
    }

}