parentdao.java

java写的一个简单的bbs系统

package com.ibm.dao;

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

import com.ibm.common.DBConnection;
import com.ibm.vo.ParentVO;

public class ParentDAO {
  private static ParentDAO pdao=null;
  private PreparedStatement ps;
private ResultSet rs;

  private ParentDAO()
  {
	  
  }
  
  public static ParentDAO getInstance()
  {
	  if(pdao == null)
	  {
		  pdao=new ParentDAO();
		  return pdao;
	  }else
	  {
		  return pdao;
	  }
  }
  
  /**
   * 取出所有的主版块列表
   * @param con
   * @return
   */
  public List queryAllParent(Connection con)
  {
	  String sql="select * from parent";
	  List list=new ArrayList();
//	  ParentVO pvo=null;
	  try {
		ps=con.prepareStatement(sql);
		rs=ps.executeQuery();
		while(rs.next())
		{
			ParentVO pvo= new ParentVO();
//			pvo=ParentVO.getInstance();
			pvo.setParentid(rs.getInt("parentid"));
			pvo.setParentname(rs.getString("parentname"));
			
			list.add(pvo);
		}
	} catch (SQLException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
		System.out.println("ParentDAO.queryAllParent");
	}
//	finally{
//		DBConnection.getInstance().close(null, ps, null, rs, con);
//	}
	return list;
  }
}