tfiledao.java

持久层hibernate技术使用的一个例子

package cn.hope.front.pojo.dao;

import java.util.List;

import org.apache.log4j.Logger;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Query;
import cn.hope.front.pojo.TFile;
import cn.hope.front.pojo.base.BaseTFileDAO;

public class TFileDAO extends BaseTFileDAO {
	Logger log = Logger.getLogger(TFileDAO.class.getName());

	/**
	 * Default constructor. Can be used in place of getInstance()
	 */
	public TFileDAO() {
	}

	private int count = 0;

	public int getCount() {
		return this.count;
	}

	/**
	 * 插入数据方法
	 * 
	 * @param tFile
	 * @return
	 * @throws HibernateException
	 */
	public Integer insert(TFile tFile) throws HibernateException {
		try {
			initialize();// 初始化session
			return this.save(tFile);// 调用生成好的父类方法save(),返回被插入数据的主键
		} catch (HibernateException e) {
			log.error(e);
			e.printStackTrace();
			throw new HibernateException(e);
		} finally {
			closeCurrentThreadSessions();// 关闭当前session
		}
	}

	public void modify(TFile tFile) throws HibernateException {
		try {
			initialize();
			this.update(tFile);
		} catch (HibernateException e) {
			log.error(e);
			e.printStackTrace();
			throw new HibernateException(e);
		} finally {
			closeCurrentThreadSessions();
		}
	}

	public TFile searchByKey(Integer id) throws HibernateException {
		TFile tFile = null;
		String sqlStr = "select tFile from TFile tFile where tFile.flag='0' and tFile.tfId='"
				+ id + "'";
		try {
			initialize();
			List list = this.getSession().find(sqlStr);
			if (list.size() > 0) {
				tFile = (TFile) list.get(0);
			}
		} catch (HibernateException e) {
			log.error(e);
			e.printStackTrace();
			throw new HibernateException(e);
		} finally {
			closeCurrentThreadSessions();
		}
		return tFile;
	}

	/**
	 * 
	 * @param tFile
	 *            //存放查询条件
	 * @param start
	 *            //分页起始记录数
	 * @param range
	 *            //分页显示记录数
	 * @param isEq
	 *            //某条件是否完全匹配(可以不加)
	 * @return
	 * @throws HibernateException
	 */
	public List search(TFile tFile, int start, int range, boolean isEq)
			throws HibernateException {
		List list = null;
		StringBuffer sqlCnt = new StringBuffer();// 取总记录数
		StringBuffer sqlStr = new StringBuffer();// 长字符串的拼合一定要用StringBuffer.append()
		StringBuffer condition = new StringBuffer();// 查询条件
		sqlCnt.append("select count(tFile.id) from TFile tFile where tFile.flag='0' ");
		sqlStr.append("select tFile from TFile tFile where tFile.flag='0' ");

		/* 通过tFile中存储的条件组装HQL语句 */

		try {
			initialize();
			Query queryCnt = this.getSession().createQuery(
					sqlCnt.toString() + condition);// 通过hibernate的Query方法查询数据库(自己看文档)
			Integer count = (Integer) queryCnt.uniqueResult();// 得到总记录数
			this.count = count.intValue();

			condition.append(" order by tFile.tfTime desc");// 加入排序条件
			Query query = this.getSession().createQuery(
					sqlStr.toString() + condition);
			query.setFirstResult(start);// 设置查询起始记录数
			query.setMaxResults(range);// 设置查询总记录数
			list = query.list();
		} catch (HibernateException e) {
			log.error(e);
			e.printStackTrace();
			throw new HibernateException(e);
		} finally {
			closeCurrentThreadSessions();
		}
		return list;
	}
}