bd.java

一个jsp翻页的小例子

package com.page;

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

import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspWriter;

import com.page.inc.SQLDataSource;

public class BD {
	
	Connection con;
	private int id;
	private String c_bd;
	private String c_tbd;
	
	public BD()
	{
		
	}
	public BD( int id, String c_bd, String c_tbd) {
		super();
	
		this.id = id;
		this.c_bd = c_bd;
		this.c_tbd = c_tbd;
	}
	public String getC_bd() {
		return c_bd;
	}
	public void setC_bd(String c_bd) {
		this.c_bd = c_bd;
	}
	public String getC_tbd() {
		return c_tbd;
	}
	public void setC_tbd(String c_tbd) {
		this.c_tbd = c_tbd;
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	
	public List getAll() throws Exception
	{
		
		List list = new ArrayList();
		
		con = SQLDataSource.getConn();
		String sql = "select id,c_bd,c_tbd from t_bdxx";
		ResultSet rs = con.createStatement().executeQuery(sql);
		
		while(rs.next())
		{
			int id = rs.getInt("id");
			String c_bd = rs.getString("c_bd");
			String c_tbd = rs.getString("c_tbd");
			BD bd = new BD(id,c_bd,c_tbd);
			
			list.add(bd);		
		}
		return list;
	}
	
	
	public void list(HttpServletRequest request, JspWriter out) throws Exception
	{
		String tmp = (String)request.getParameter("page");
		
		if(tmp!= null)
		{
			listpage(request,out,Integer.parseInt(tmp));
		}else
		{
			listpage(request,out,1);
		}
	}
	
	
	public void listpage(HttpServletRequest request, JspWriter out,int page)throws Exception
	{
		List list = this.getAll();
		
		int totalcount = 0 ;//记录总数
		int count = 10; //每页显示数
		int totalPages = 0; //页数
		
		totalcount = list.size(); //检索当前行编号
		totalPages = (totalcount + count - 1)/count;//计算总页数
	
		if(page<=1)
		{
			page = 1;
		}
		if(page>totalPages)
		{
			page = totalPages;
		}
		int begin = (page - 1)* count + 1; //开始行
		int end = page * count;				//结束行
		if(begin<=1)
		{
			begin = 1;
		}
		con = SQLDataSource.getConn();
		String sql = "select id,c_bd,c_tbd from t_bdxx order by id";
		
		ResultSet rs = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE).executeQuery(sql);
		out.println("<table>");
		for(int x = begin;x<=end; x++) //将指针移动到此ResultSet 对象的给定行编号
		{
			if(rs.absolute(x));
			{
				out.println("<tr align=\"center\">");
				out.println("<td width=\"20%\" noWrap>"+rs.getInt("id")+"</td>");
				out.println("<td width=\"20%\" noWrap>"+rs.getString("c_bd")+"</td>");
				out.println("<td width=\"20%\" noWrap>"+rs.getString("c_tbd")+"</td>");
				out.println("</tr>");
			}
			if(rs.next()==false) break;
		}
		out.println("</table>");
	  
		//输出翻页用到的连接“上一页”和“下一页”	
		out.println("<table>");
		
		out.println("<tr>");
		
		out.println("<td colspan=\"6\">");
		
		out.println("<div align=\"center\">总有"+totalcount+"条信息&nbsp;&nbsp;页次:"+page+"/"+totalPages+"页&nbsp;&nbsp;&nbsp;&nbsp;");
		if(begin<=1)
		{
			out.println("首页&nbsp;");
			out.println("上一页&nbsp;");
		}else
		{
			out.println("<a href=\"?page=1\">首页</a>&nbsp;");
			out.println("<a href=\"?page="+(page-1)+"\">上一页</a>");
		}
		if(page>=totalPages)
		{
			out.println("下一页&nbsp;");
			out.println("尾页&nbsp;");
		}
		else
		{
			out.println("<a href=\"?page="+(page+1)+"\">下一页</a>&nbsp;");
			out.println("<a href=\"?page="+totalPages+"\">尾页</a>");
		}
		out.println("</table>");
		
	}

}