Sql 分页查询语句 ： select * from goods limit ?,?
limit 开始查询位置（从0开始，0对应数据库中的第一条数据），查询记录的条数
GoodsDao.java:
//每页记录数 private int pagesize = 6; //根据page查询该页的记录 public List<Goods> findByPage(int page) throws SQLException { if(page < 1){ page = 1; } int offset = 0; String sql = "select * from tdb_goods limit ?,?"; //QueryRunner Dbutil 数据库链接池 提供的对象 //JDBCUtil_DBCP.getDataSource() 通过工具类得到一个数据源 QueryRunner queryRunner = new QueryRunner(JDBCUtil_DBCP.getDataSource()); Object[] params = {offset + (page - 1) * pagesize,pagesize}; List<Goods> list = null; try { list = (List<Goods>) queryRunner.query(sql, new BeanListHandler(Goods.class),params); } catch (SQLException e) { throw new SQLException("查找失败"); } return list; } //查询记录数并返回最大页数 public int maxpage(){ String sql = "select count(*) from tdb_goods"; QueryRunner queryRunner = new QueryRunner(JDBCUtil_DBCP.getDataSource()); int maxpage = 1; try { int count = Integer.parseInt(((Long)(((Object[]) queryRunner.query(sql, new ArrayHandler()))[0])).toString()); maxpage = count % pagesize == 0? count / pagesize : count / pagesize + 1; } catch (SQLException e) { e.printStackTrace(); } return maxpage; }
Service.java:
public class Service { GoodsDao goodsDao =new GoodsDao();//根据页数查询数据 public List<Goods> show_goos(int page){ try { return goodsDao.findByPage(page); } catch (SQLException e) { System.out.println(e.getMessage());; } return null; } //获得最大页数 public int getmaxPage() { return goodsDao.maxpage(); } }
Servlet.java:
import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.hyl.bean.Goods; import com.hyl.service.Service; public class MyServlet extends HttpServlet { @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { Service service = new Service(); //判断页面传过来的page数 int maxpage = service.getmaxPage(); if(req.getParameter("page")==null){ //设置初始默认第一页 req.setAttribute("page", 1); }else if(Integer.parseInt(req.getParameter("page"))>maxpage){ //设置默认最大为maxpage req.setAttribute("page", maxpage); }else if(Integer.parseInt(req.getParameter("page"))==0){ //设置设置默认最大为maxpage req.setAttribute("page", maxpage); }else{ //设置当前页数(便于jsp中给当前页设置特殊属性) req.setAttribute("page", Integer.parseInt(req.getParameter("page"))); } List<Goods> list = service.show_goos(Integer.parseInt(req.getAttribute("page").toString())); req.setAttribute("maxpage", maxpage); req.setAttribute("list", list); getServletContext().getRequestDispatcher("/goods.jsp").forward(req, resp); } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doPost(req, resp); } }
用于展示数据的jsp页面：goods.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>goods page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> </head> <body> <table border="1px"> <tr> <td>编号</td> <td>商品</td> <td>类型</td> <td>厂商</td> <td>价格</td> <td>是否出售</td> <td>是否售空</td> </tr> <c:forEach var="g" items="${list}"> <tr> <td>${g.goods_id}</td> <td>${g.goods_name}</td> <td>${g.goods_cate}</td> <td>${g.brand_name}</td> <td>${g.goods_price}</td> <td>${g.is_show}</td> <td>${g.is_saleoff}</td> </tr> </c:forEach> </table> <c:if test="${page!=1}"> <a href="myservlet?page=1">首页</a> </c:if> <c:if test="${page>1}"> <a href="myservlet?page=${page-1 }">上一页</a> </c:if> <c:forEach begin="1" step="1" end="${maxpage }" var="a"> <c:choose> <c:when test="${page==a}"> <a href="myservlet?page=${a}" style="color: red">${a}</a> </c:when> <c:otherwise> <a href="myservlet?page=${a}">${a}</a> </c:otherwise> </c:choose> </c:forEach> <c:if test="${page<maxpage}"> <a href="myservlet?page=${page+1 }">下一页</a> </c:if> <c:if test="${page!=maxpage}"> <a href="myservlet?page=${maxpage}">尾页</a> </c:if> </body> </html>
注：servlet与jsp页面传值过程中变量名要一致（细节问题）
补：EL表达式中c:forEach中的items不可为单一的一个对象或是基本数据，会报错
结果如下：
Over