Hibernate常用代码模板

工具类HibernateUtil.java:

package com.cz.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sesession
	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,相当于该session已经和线程绑定
			threadLocal.set(session);
		}
		return session;
		
		
	}
	
	//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();
			}
			
		}
		
	}

//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;
	}
	
//提供一个统一的查询方法 总是返回一个对象
	public static Object uniqueQuery(String hql,String [] parameters){
		
		Session s=null;
		Object obj=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]);
				}
			}
			obj=query.uniqueResult();
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException(e.getMessage());
			// TODO: handle exception
		}finally{
			
			if(s!=null&&s.isOpen()){
				s.close();
			}
			
		}
		return obj;
	}
	
}

测试类TestMain.java:

package com.cz.view;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.criterion.Restrictions;

import com.cz.util.*;
import com.sina.domain.Course;
import com.sina.domain.Studcourse;
import com.sina.domain.Student;
public class TestMain{

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		//这里我们使用增强的HibernateUtil来完成curd.
	/*	String hql="select sname,saddress from Student where sdept=? and sage>?";
		String parameters[]={"计算机系","3"};
		List<Object[]> list= HibernateUtil.executeQuery(hql,parameters);
		for(Object[] s: list){
			System.out.println(s[0].toString()+" "+s[1].toString());
		}*/
		
		//使用工具分页
	/*	String hql="select sname,saddress from Student order by sage";
		String parameters[]=null;
		List<Object[]> list= HibernateUtil.
		executeQueryByPage(hql, parameters, 2, 3) ;
		for(Object[] s: list){
			System.out.println(s[0].toString()+" "+s[1].toString());
		}*/
		
		/*添加*/
	/*	Course c=new Course();
		c.setCname("servlet");
		c.setCid(4L);
		HibernateUtil.save(c);*/
		
		//调用修改/删除
	/*	String hql="update Student set sage=sage+1 where sdept=?";
		String parameters[]={"计算机系"};
		try {
			HibernateUtil.executeUpdate(hql, parameters);
		} catch (Exception e) {
			System.out.println(e.getMessage());
			// TODO: handle exception
		}*/
		//请显示所有选择了21号课程的学生信息
	/*	String hql="select student.sname,student.sdept from Studcourse where course.cid=?";
		String parameters[]={"21"};
		List<Object[]> list=HibernateUtil.executeQuery(hql, parameters);
		for(Object[] s:list){
			System.out.println(s[0].toString()+" "+s[1].toString());
		}*/
		
	/*	String hql="from Studcourse where course.cid=21";
		List<Studcourse> list=HibernateUtil.executeQuery(hql, null);
		//懒加载我们有一个章节详解.
		for(Studcourse sc:list){
			System.out.println(sc.getGrade()+sc.getStudent().getSname());
		}*/

		//查询年龄大于10岁的学生 criteria
		
		Session s=HibernateUtil.getCurrentSession();
		Transaction tx=s.beginTransaction();
		Criteria cri=s.createCriteria(Student.class);
		//添加检索条件
		cri.add(Restrictions.gt("sage", new Long(10)));
		List<Student> list=cri.list();
		for(Student s1: list){
			System.out.println(s1.getSname());
		}
		
		tx.commit();
	}

}