studentdao.java

一个简单的登陆系统

package com.niit.dao.hibernate;

import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.LockMode;
import org.springframework.context.ApplicationContext;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import com.niit.dao.IStudentDAO;
import com.niit.model.Student;

/**
 * A data access object (DAO) providing persistence and search support for
 * Student entities. Transaction control of the save(), update() and delete()
 * operations can directly support Spring container-managed transactions or they
 * can be augmented to handle user-managed Spring transactions. Each of these
 * methods provides additional information for how to configure it for the
 * desired type of transaction control.
 * 
 * @see com.niit.model.Student
 * @author MyEclipse Persistence Tools
 */

public class StudentDAO extends HibernateDaoSupport implements IStudentDAO
{
	private static final Log log = LogFactory.getLog(StudentDAO.class);
	// property constants
	public static final String SNAME = "sname";
	public static final String CITY = "city";
	public static final String AGE = "age";

	protected void initDao()
	{
		// do nothing
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#save(com.niit.model.Student)
	 */
	public void save(Student transientInstance)
	{
		log.debug("saving Student instance");
		try
		{
			getHibernateTemplate().save(transientInstance);
			log.debug("save successful");
		}
		catch (RuntimeException re)
		{
			log.error("save failed", re);
			throw re;
		}
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#delete(com.niit.model.Student)
	 */
	public void delete(Student persistentInstance)
	{
		log.debug("deleting Student instance");
		try
		{
			getHibernateTemplate().delete(persistentInstance);
			log.debug("delete successful");
		}
		catch (RuntimeException re)
		{
			log.error("delete failed", re);
			throw re;
		}
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#findById(java.lang.Integer)
	 */
	public Student findById(java.lang.Integer id)
	{
		log.debug("getting Student instance with id: " + id);
		try
		{
			Student instance = (Student) getHibernateTemplate().get(
					"com.niit.model.Student", id);
			return instance;
		}
		catch (RuntimeException re)
		{
			log.error("get failed", re);
			throw re;
		}
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#findByExample(com.niit.model.Student)
	 */
	public List findByExample(Student instance)
	{
		log.debug("finding Student instance by example");
		try
		{
			List results = getHibernateTemplate().findByExample(instance);
			log.debug("find by example successful, result size: "
					+ results.size());
			return results;
		}
		catch (RuntimeException re)
		{
			log.error("find by example failed", re);
			throw re;
		}
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#findByProperty(java.lang.String, java.lang.Object)
	 */
	public List findByProperty(String propertyName, Object value)
	{
		log.debug("finding Student instance with property: " + propertyName
				+ ", value: " + value);
		try
		{
			String queryString = "from Student as model where model."
					+ propertyName + "= ?";
			return getHibernateTemplate().find(queryString, value);
		}
		catch (RuntimeException re)
		{
			log.error("find by property name failed", re);
			throw re;
		}
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#findBySname(java.lang.Object)
	 */
	public List findBySname(Object sname)
	{
		return findByProperty(SNAME, sname);
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#findByCity(java.lang.Object)
	 */
	public List findByCity(Object city)
	{
		return findByProperty(CITY, city);
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#findByAge(java.lang.Object)
	 */
	public List findByAge(Object age)
	{
		return findByProperty(AGE, age);
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#findAll()
	 */
	public List findAll()
	{
		log.debug("finding all Student instances");
		try
		{
			String queryString = "from Student";
			return getHibernateTemplate().find(queryString);
		}
		catch (RuntimeException re)
		{
			log.error("find all failed", re);
			throw re;
		}
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#merge(com.niit.model.Student)
	 */
	public Student merge(Student detachedInstance)
	{
		log.debug("merging Student instance");
		try
		{
			Student result = (Student) getHibernateTemplate().merge(
					detachedInstance);
			log.debug("merge successful");
			return result;
		}
		catch (RuntimeException re)
		{
			log.error("merge failed", re);
			throw re;
		}
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#attachDirty(com.niit.model.Student)
	 */
	public void attachDirty(Student instance)
	{
		log.debug("attaching dirty Student instance");
		try
		{
			getHibernateTemplate().saveOrUpdate(instance);
			log.debug("attach successful");
		}
		catch (RuntimeException re)
		{
			log.error("attach failed", re);
			throw re;
		}
	}

	/* (non-Javadoc)
	 * @see com.niit.dao.hibernate.IStudentDAO#attachClean(com.niit.model.Student)
	 */
	public void attachClean(Student instance)
	{
		log.debug("attaching clean Student instance");
		try
		{
			getHibernateTemplate().lock(instance, LockMode.NONE);
			log.debug("attach successful");
		}
		catch (RuntimeException re)
		{
			log.error("attach failed", re);
			throw re;
		}
	}

	public static IStudentDAO getFromApplicationContext(ApplicationContext ctx)
	{
		return (IStudentDAO) ctx.getBean("StudentDAO");
	}
}