initdata.java

实现一些hibernate底层的东西

package com.bjsxt.hibernate;


import java.text.SimpleDateFormat;
import java.util.Date;

import org.hibernate.Session;


public class InitData {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Session session = null;
		try{
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			for( int i = 0 ; i < 10 ; i++ ){
				Classes classes = new Classes();
				classes.setName( "claub" + i );
				session.save( classes );
				for( int j = 0 ; j < 10 ; j++ ){
					Student student = new Student();
					student.setName( "claub" + i + "_footballer" + j );
					student.setCreateDate( randomDate("2008-01-01","2008-03-01"));
					
					student.setClasses(classes);
					session.save( student );
				}
				
				
			}
			
			for(int i=0; i<5; i++){
				Classes classes = new Classes();
				classes.setName("no_claub"+i);
				session.save(classes);
			}
			
			for(int i=0; i<10; i++){
				Student student = new Student();
				student.setName("no_football"+i);
				session.save(student);
			}
			
			
			session.getTransaction().commit();
			
		}catch( Exception e ){
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally{
			HibernateUtils.closeSession(session);
		}
	}
	
	private static Date randomDate(String beginDate,String endDate){
		try {
			SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
			Date start = format.parse(beginDate);
			Date end = format.parse(endDate);
			
			if(start.getTime() >= end.getTime()){
				return null;
			}
			
			long date = random(start.getTime(),end.getTime());
			
			return new Date(date);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
	
	private static long random(long begin,long end){
		long rtn = begin + (long)(Math.random() * (end - begin));
		if(rtn == begin || rtn == end){
			return random(begin,end);
		}
		return rtn;
	}

}