Hibernate多对一（注解）

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;
    }
}

package cqvie.yjq.domain;

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 = "department_", catalog = "test")
public class Department implements java.io.Serializable {

    private static final long serialVersionUID = 2076837731637660357L;
    
    @Id
    @GenericGenerator(name = "generator", strategy = "uuid")
    @GeneratedValue(generator = "generator")
    @Column(name = "depid", unique = true, nullable = false)//nullable = false表示该字段不为空
    private String depid;
    @Column(name = "name", nullable = false, length = 20)
    private String name;
    
    public String getDepid() {
        return depid;
    }
    public void setDepid(String depid) {
        this.depid = depid;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    
}

package cqvie.yjq.domain;

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_", catalog = "test")
public class Student implements java.io.Serializable {

    private static final long serialVersionUID = 8640757615294410421L;
    
    @Id
    @GenericGenerator(name = "generator", strategy = "uuid")
    @GeneratedValue(generator = "generator")
    @Column(name = "stuid", unique = true, nullable = false)
    private String stuid;
    @Column(name = "name", nullable = false, length = 20)
    private String name;
    @ManyToOne
    @JoinColumn(name = "depid")
    private Department dept;
    
    public String getStuid() {
        return stuid;
    }
    public void setStuid(String stuid) {
        this.stuid = stuid;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Department getDept() {
        return dept;
    }
    public void setDept(Department dept) {
        this.dept = dept;
    }
    
    
}

package cqvie.yjq.View;

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

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

public class Test {

    public static void main(String[] args) {

        //通过获取session让hibernate框架运行(config --> 加载hibernate.cfg.xml)
        Session session = null;
        Transaction tx = null;
        try {
            session =  HibernataUtil.getCurrentSession();
            tx = session.beginTransaction();

            Student stu = new Student();
            stu.setName("王敏");
            
            Department dep = new Department();
            dep.setName("财务部");
            Department dep1 = new Department();
            dep1.setName("人事部");
            
            stu.setDept(dep1);
            
            session.save(stu);
            session.save(dep);
            session.save(dep1);
            
            tx.commit();
        } catch (Exception e) {
            if(tx != null) {
                tx.rollback();
            }
        } finally {
            if(session != null && session.isOpen()) {
                session.close();
            }
        }
    }

}

<?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.Department" />
    <mapping class="cqvie.yjq.domain.Student" />
</session-factory>

</hibernate-configuration>