b0f901867687001d158dc7ac74c4dcae

一个相对比较简单的留言簿！功能还比较齐全！

package com.pure35.database;
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.pure35.vo.MessageVo;
public class MessageDao {
	Connection con=null;
	PreparedStatement pm=null;
	ResultSet rs;
	MessageVo message;
	
	public void updateMessage(String sql){
		try {
			con=DBConn.getConnection();//连接数据库
			pm=con.prepareStatement(sql);
			pm.executeUpdate();
			
		} catch (SQLException e) {
			
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			DBConn.closeConnection();			
		}		
	}
	
	public List queryMessage(String sql ){
		List list=new ArrayList();
    	try {
    		con=DBConn.getConnection();
			pm=con.prepareStatement(sql);
			rs=pm.executeQuery();
			while(rs.next()){
				
				int id=rs.getInt("id");;
			    String subject=rs.getString("subject");
				 Date  mdate=rs.getDate(3);
				 String username=rs.getString("userrname");
				 String content=rs.getString("content");
				
				message=new MessageVo();
				message.setContent(content);
				message.setId(id);
				message.setMdate(mdate);
				message.setUsername(username);
				message.setSubject(subject);				
				list.add(message);				
			}
			
		} catch (SQLException e) {
			
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			try {
				rs.close();
				pm.close();
				DBConn.closeConnection();
			} catch (SQLException e) {
				e.printStackTrace();
			}		
		}
 		
		return list;
	}
	public int getPageCount()
	{
		 int pageSize=3;
		 int rowCount=0;
		 int pageCount=0;
		  
		 try {
				con=DBConn.getConnection();
			} catch (ClassNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			String sql="select count(*) from message";
			try {
				ps=con.prepareStatement(sql);
				rs=ps.executeQuery();
				if(rs.next())
				{
					rowCount=rs.getInt(1);
				}
				if(rowCount%pageSize==0)
				{
					pageCount=rowCount/pageSize;
				}
				else
				{
					pageCount=rowCount/pageSize+1;
				}	
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}finally
			{
				DBConn.closeConnection();
			}
			 
			  return pageCount;
	
	
}