classesdaoimp.java

学校的课程管理及选课系统

package org.wangsong.dao.imp;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.wangsong.dao.ClassesDAO;
import org.wangsong.dao.hibernate.HibernateUtil;
import org.wangsong.domain.Classes;
import org.wangsong.domain.ClassesForTea;
import org.wangsong.domain.CourseForStu;
 

public class ClassesDAOImp implements ClassesDAO
{
    
	private static Log log = LogFactory.getLog(ClassesDAOImp.class);

	 
	public List getClasses()
	{
		try
		{
			 
	  	    Session s = HibernateUtil.currentSession();
			// 开始事务
			HibernateUtil.beginTransaction();
			// 执行操作
			List results = s.createQuery("from Classes cla").list();
			// 提交事务
			HibernateUtil.commitTransaction();
			// 关闭Session
			HibernateUtil.closeSession();
			// 返回结果
			if (results != null && results.size() > 0)
			{
				return results;
			}
		}
		catch (HibernateException e)
		{
			log.fatal(e);
		}
		return null;
	}

	// 删除指定班级编号的班级信息
	 
	public boolean deleteClassesByID(String id)
	{
		try
		{
			Session s = HibernateUtil.currentSession();
			HibernateUtil.beginTransaction();
			Classes cla = (Classes) s.load(Classes.class, id);
			System.out.println(cla.getId());
			s.delete(cla);
			HibernateUtil.commitTransaction();
			HibernateUtil.closeSession();
			return true;
		}
		catch (HibernateException e)
		{
			log.fatal(e);
		}
		return false;
	}

	// 通过班级编号获得班级信息
	public Classes getClassesByID(String id)
	{
		try
		{
			Session s = HibernateUtil.currentSession();
			HibernateUtil.beginTransaction();
			Classes cla = (Classes) s.load(Classes.class, id);
			HibernateUtil.commitTransaction();
			HibernateUtil.closeSession();
			return cla;
		}
		catch (HibernateException e)
		{
			log.fatal(e);
		}
		return null;
	}

	// 更新班级的信息
	public boolean updateClasses(Classes cla)
	{
		try
		{
			Session s = HibernateUtil.currentSession();
			HibernateUtil.beginTransaction();
			s.update(cla);
			System.out.println("update Classes id =" + cla.getId());
			HibernateUtil.commitTransaction();
			HibernateUtil.closeSession();
			return true;
		}
		catch (HibernateException e)
		{
			log.fatal(e);
		}
		return false;
	}

	// 保存某班级的信息
	public boolean saveClasses(Classes cla)
	{
		try
		{
			Session s = HibernateUtil.currentSession();
			HibernateUtil.beginTransaction();
			s.saveOrUpdate(cla);
			System.out.println("save Classes id =" + cla.getId());
			HibernateUtil.commitTransaction();
			HibernateUtil.closeSession();
			return true;
		}
		catch (HibernateException e)
		{
			log.fatal(e);
		}
		return false;
	}
	public List getClassesForTea(String teaid) throws SQLException
	{
		ArrayList results = new ArrayList();
		try
		{

			Session s = HibernateUtil.currentSession();

			Connection conn = s.connection();
			Statement sql = conn.createStatement();
			System.out.println("开始查询");
			ResultSet rs = sql.executeQuery("select classes.id , course.name from  course,classes,teacher where teacher.id ='"+ teaid +"' and  teacher.id = classes.tea_id and course.id=classes.cour_id" ); 
			System.out.println("sql执行完毕");		  
			while (rs.next())
			{
				ClassesForTea classesfortea=new ClassesForTea(); 
				classesfortea.setClassid(rs.getString(1));
				classesfortea.setClassname(rs.getString(2));
	 		    results.add(classesfortea);
			}
			rs.close();
			sql.close();
			System.out.print("查询结束");
			// 关闭Session
			HibernateUtil.closeSession();
			if (results != null && results.size() > 0)
			{
				return results;
			}
		}
		catch (HibernateException e)
		{

            e.printStackTrace();
		}
	
		return null;
		
		
	}
	 
	
}