fenye.java

高效的jsp分页查询

package com.jida.gt.fenye;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import com.jida.gt.db.DataBaseConnection;

public class FenYe {
	
	int PageSize=3;//每页显示多少行
   	
   	int ShowPage=1;//要显示那一页
   	
   	int RowCount=0;//表一共有多少行
   	
   	int PageCount=0;//一共有多少页
   	      	
   	Statement stmt=null;
   	
   	ResultSet rs=null;
   	
   	Connection conn=null;
   	
   	public FenYe()
   	{
   		conn=new DataBaseConnection().getConnection();
   	}

   	public ResultSet queryT(String ToPage,String Table)
   	{
   		
   
   		
   		try {
   			
			stmt=conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
			String sql="SELECT * FROM "+Table;
			rs=stmt.executeQuery(sql);
			rs.last();//到表的最后一行
			RowCount=rs.getRow();//求出一共有多少行
			PageCount=((RowCount%PageSize==0)?(RowCount/PageSize):(RowCount/PageSize)+1);//根据行来确定有多少页
						
   		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		if (ToPage != null) {
			ShowPage = Integer.parseInt(ToPage);//string转化成int
			if (ShowPage > PageCount) {
				ShowPage = PageCount;
			} else if (ShowPage < 0) {
				ShowPage = 1;

			}

		}
		
		try {
			rs.absolute((ShowPage - 1) * PageSize + 1);//到那一页的第一行
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
   	

		
   		
   		return rs;
   	}

	public int getShowPage() {
		return ShowPage;
	}

	public void setShowPage(int showPage) {
		ShowPage = showPage;
	}

	public int getPageCount() {
		return PageCount;
	}

	public void setPageCount(int pageCount) {
		PageCount = pageCount;
	}

	public int getPageSize() {
		return PageSize;
	}

	public void setPageSize(int pageSize) {
		PageSize = pageSize;
	}
}