Hibernate一对多（注解）

 <?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="dialect">
         org.hibernate.dialect.MySQLDialect
     </property>
     <property name="connection.url">
         jdbc:mysql://localhost:3306/student
     </property>
     <property name="connection.username">root</property>
     <property name="connection.password">123</property>
     <property name="connection.driver_class">
         com.mysql.jdbc.Driver
     </property>
     <property name="myeclipse.connection.profile">MySQL</property>
     <property name="show_sql">true</property>
     <!-- 格式化显示SQL -->
     <property name="format_sql">true</property>

     <property name="current_session_context_class">thread</property>
     <!-- 让hibernate自动创建表  update:如果没有表则创建，有表则更新 -->
     <property name="hbm2ddl.auto">create</property>
     <mapping class="cqvie.yjq.domain.School" />
     <mapping class="cqvie.yjq.domain.Student" />
 </session-factory>

 </hibernate-configuration>

Hibernate.cfg.xml

 package cqvie.yjq.domain;

 import java.io.Serializable;

 import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.Id;
 import javax.persistence.Table;

 import org.hibernate.annotations.GenericGenerator;

 @Entity
 @Table(name = "school_2", catalog = "test")
 public class School implements Serializable {

     private static final long serialVersionUID = -9135891983324864046L;

     @Id
     @GenericGenerator(name = "generator", strategy = "uuid")
     @GeneratedValue(generator = "generator")
     @Column(name = "s_num", unique = true, nullable = false)
     private String s_num;
     @Column(name = "s_name", length = 50, nullable = false)
     private String s_name;
     @Column(name = "s_addr", length = 100, nullable = false)
     private String s_addr;

     public String getS_num() {
         return s_num;
     }
     public void setS_num(String sNum) {
         s_num = sNum;
     }
     public String getS_name() {
         return s_name;
     }
     public void setS_name(String sName) {
         s_name = sName;
     }
     public String getS_addr() {
         return s_addr;
     }
     public void setS_addr(String sAddr) {
         s_addr = sAddr;
     }
 }

实体类School

 package cqvie.yjq.domain;

 import java.io.Serializable;

 import javax.persistence.CascadeType;
 import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.Id;
 import javax.persistence.JoinColumn;
 import javax.persistence.ManyToOne;
 import javax.persistence.Table;

 import org.hibernate.annotations.GenericGenerator;

 @Entity
 @Table(name = "student_2", catalog = "test")
 public class Student implements Serializable {

     private static final long serialVersionUID = 7571983435023574040L;

     @Id
     @GenericGenerator(name = "generator", strategy = "uuid")
     @GeneratedValue( generator = "generator")
     @Column(name = "id", nullable = false, unique = true)
     private String id;

     @Column(name = "name", nullable = false, length = 20)
     private String name;

     @Column(name = "age", nullable = false, length = 3)
     private int age;

     @ManyToOne(cascade={CascadeType.ALL})
     @JoinColumn(name = "s_num")
     private School school;

     public School getSchool() {
         return school;
     }
     public void setSchool(School school) {
         this.school = school;
     }
     public String getId() {
         return id;
     }
     public void setId(String id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public int getAge() {
         return age;
     }
     public void setAge(int age) {
         this.age = age;
     }
 }

实体类Student

 package cqvie.yjq.View;

 import org.hibernate.Session;
 import org.hibernate.Transaction;

 import cqvie.yjq.Util.HibernataUtil;
 import cqvie.yjq.domain.School;
 import cqvie.yjq.domain.Student;

 public class Test {

     public static void main(String[] args) {

         Session session = null;
         Transaction tx = null;
         try {
             session =  HibernataUtil.getCurrentSession();
             tx = session.beginTransaction();
             //添加
             School sc = new School();
             sc.setS_name("重庆工业职业技术学院");
             sc.setS_addr("重庆渝北");

             Student stu = new Student();
             stu.setSchool(sc);
             stu.setAge(17);
             stu.setName("马士兵");

             session.save(stu);

             tx.commit();
         } catch (Exception e) {
             if(tx != null) {
                 tx.rollback();
             }
         } finally {
             if(session != null && session.isOpen()) {
                 session.close();
             }
         }

     }
 }

测试类Test

package cqvie.yjq.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.AnnotationConfiguration;

final public class HibernataUtil {

    private static SessionFactory sessionFactory = null;
    //使用线程局部模式
    private static ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
    private HibernataUtil() {};
    static {
        sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
    }
    //获取全新的session
    public static Session openSession() {
        return sessionFactory.openSession();
    }
    //获取和线程关联的session
    public 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，相当于已经和线程绑定
            threadLocal.set(session);
        }
        return session;
    }

    //提供一个统一的修改和删除方法（批量）
    public static void executeUpdate(String hql, String[] parameters) {
        Session s = null;
        Transaction ts = null;
        try {
            s = openSession();
            ts = 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();
            ts.commit();
        } catch(Exception e) {
            e.printStackTrace();
            throw new RuntimeException();
        } finally {
            if(s != null && s.isOpen()) {
                s.close();
            }
        }
    }

    //提供一个统一的添加方法
    public static void sava(Object obj) {
        Session s = null;
        Transaction ts = null;
        try {
            s = openSession();
            ts = s.beginTransaction();
            s.save(obj);
            ts.commit();
        } catch (Exception e) {
            if(ts != null) {
                ts.rollback();
            }
            throw new RuntimeException();
        } finally {
            if(s != null && s.isOpen()) {
                s.close();
            }
        }
    }

    //提供一个统一的查询方法（分页）
    @SuppressWarnings("unchecked")
    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();
        } 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=?
    @SuppressWarnings("unchecked")
    public 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();
        } finally {
            if(s != null && s.isOpen()) {
                s.close();
            }
        }
        return list;
    }
}

工具类HibernateUtil