jsp+servlet实现分页

准备工作

1.数据库和表

创建自己的数据库和表

2.创建项目

demo

3.引入jar包

4.创建包结构，导入工具类，引入配置文件
javabean：product

package com.domain;

public class Product {
	private String pid;
	private String pname;
	private Double market_price;
	private Double shop_price;
	private String pimage;
	private String pdate;
	private String pdesc;
	public String getPid() {
		return pid;
	}
	public void setPid(String pid) {
		this.pid = pid;
	}
	public String getPname() {
		return pname;
	}
	public void setPname(String pname) {
		this.pname = pname;
	}
	public Double getMarket_price() {
		return market_price;
	}
	public void setMarket_price(Double market_price) {
		this.market_price = market_price;
	}
	public Double getShop_price() {
		return shop_price;
	}
	public void setShop_price(Double shop_price) {
		this.shop_price = shop_price;
	}
	public String getPimage() {
		return pimage;
	}
	public void setPimage(String pimage) {
		this.pimage = pimage;
	}
	public String getPdate() {
		return pdate;
	}
	public void setPdate(String pdate) {
		this.pdate = pdate;
	}
	public String getPdesc() {
		return pdesc;
	}
	public void setPdesc(String pdesc) {
		this.pdesc = pdesc;
	}
}

这里主要说一下模型PageModel

package com.domain;
import java.util.List;
/**
 * 存放分页相关的数据
 *
 */
public class PageModel {
	//基本属性
	private int currentPageNum;//当前页数，由用户指定				*
	private int pageSize = 5 ;//每页显示的条数，固定的				*
	private int totalRecords;//总记录条数，数据库查出来的			    *
	private int totalPageNum;//总页数，计算出来的					*
	private int startIndex;//每页开始记录的索引，计算出来的			    *
	private int prePageNum;//上一页							    *
	private int nextPageNum;//下一页							    *

	private List list;//已经分好页的结果集,该list中只有10条记录
	//扩展属性
	//一共每页显示9个页码按钮
	private int startPage;//开始页码
	private int endPage;//结束页码
	
	//完善属性
	private String url;

	//要想使用我的分页，必须给我两个参数。一个是要看哪一页，另一个是总记录条数
	public PageModel(int currentPageNum,int totalRecords,int pageSize){
		this.currentPageNum = currentPageNum;
		this.totalRecords = totalRecords;
		this.pageSize=pageSize;
		
		//计算查询记录的开始索引
		startIndex = (currentPageNum-1)*pageSize;
		//计算总页数
		totalPageNum = totalRecords%pageSize==0?(totalRecords/pageSize):(totalRecords/pageSize+1);
		startPage = currentPageNum - 4; //5
		endPage = currentPageNum + 4;  //13
		//看看总页数够不够9页
		if(totalPageNum>9){
			//超过了9页
			if(startPage < 1){
				startPage = 1;
				endPage = startPage+8;
			}
			if(endPage>totalPageNum){
				endPage = totalPageNum;
				startPage = endPage-8;
			}
		}else{
			//不够9页
			startPage = 1;
			endPage = totalPageNum;
		}
	}

	public String getUrl() {
		return url;
	}

	public void setUrl(String url) {
		this.url = url;
	}
	
	public int getStartPage() {
		return startPage;
	}

	public void setStartPage(int startPage) {
		this.startPage = startPage;
	}

	public int getEndPage() {
		return endPage;
	}

	public void setEndPage(int endPage) {
		this.endPage = endPage;
	}
	public int getPrePageNum() {
		prePageNum = currentPageNum-1;
		if(prePageNum<1){
			prePageNum = 1;
		}
		return prePageNum;
	}
	public int getNextPageNum() {
		nextPageNum = currentPageNum+1;
		if(nextPageNum>totalPageNum){
			nextPageNum = totalPageNum;
		}
		return nextPageNum;
	}
	public int getCurrentPageNum() {
		return currentPageNum;
	}
	public void setCurrentPageNum(int currentPageNum) {
		this.currentPageNum = currentPageNum;
	}
	public int getPageSize() {
		return pageSize;
	}
	public void setPageSize(int pageSize) {
		this.pageSize = pageSize;
	}
	public int getTotalRecords() {
		return totalRecords;
	}
	public void setTotalRecords(int totalRecords) {
		this.totalRecords = totalRecords;
	}
	public int getTotalPageNum() {
		return totalPageNum;
	}
	public void setTotalPageNum(int totalPageNum) {
		this.totalPageNum = totalPageNum;
	}
	public int getStartIndex() {
		return startIndex;
	}
public void setStartIndex(int startIndex) {
		this.startIndex = startIndex;
	}

	public void setPrePageNum(int prePageNum) {
		this.prePageNum = prePageNum;
	}

	public void setNextPageNum(int nextPageNum) {
		this.nextPageNum = nextPageNum;
	}

	public List getList() {
		return list;
	}

	public void setList(List list) {
		this.list = list;
	}

}

5.准备好页面

如下图

index页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>







	
分页demo
	
分页展示所有的商品

运行：

分页展示所有的商品的实现：FIndAllServlet

package com.web.servlet;

import java.io.IOException;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.domain.PageModel;
import com.domain.Product;
import com.service.ProductService;

/**
 * Servlet implementation class FindAllServlet
 */
public class FindAllServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//从客户端获取参数
		int num = Integer.parseInt(request.getParameter("num"));
		//调用service层 完成查询
		try {
			PageModel pm = new ProductService().findAll(num);
			request.setAttribute("page", pm);
			request.getRequestDispatcher("/product_list.jsp").forward(request, response);
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}

}

调用service 完成实现

package com.service;

import java.sql.SQLException;
import java.util.List;

import com.dao.ProductDao;
import com.domain.PageModel;
import com.domain.Product;

public class ProductService {

public PageModel findAll(int num) throws SQLException {
	ProductDao dao = new ProductDao();
	//设置一页显示的商品个数
	int pageSize = 3;
	//获取总的商品个数
	int totalRecords = dao.getTotalRecords();
	//初始化模型
	PageModel pm = new PageModel(num,totalRecords,pageSize);
	//获取所有的商品
	List list = dao.findAll(pm.getStartIndex(),pm.getPageSize());
	pm.setList(list);
	pm.setUrl("/FindAllServlet");
	return pm;
}

}

dao层

package com.dao;

import java.sql.SQLException;
import java.util.List;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;

import com.domain.Product;
import com.utils.DataSourceUtils;

public class ProductDao {
	
	public int getTotalRecords() throws SQLException {
		//创建QuertyRunner
		QueryRunner qr = new QueryRunner(DataSourceUtils.getDataSource());
		// 编写sql语句
		String sql = "select count(*) from product";
		// 执行sql
		return ((Long)qr.query(sql, new ScalarHandler())).intValue();
	}

	public List findAll(int startIndex, int pageSize) throws SQLException {
		// 创建QuertyRunner
		QueryRunner qr = new QueryRunner(DataSourceUtils.getDataSource());
		// 编写sql语句
		String sql = "select * from product limit ?,?";
		//为占位符赋值
		Object[] params = {startIndex,pageSize};
		// 执行sql
		return qr.query(sql, new BeanListHandler<>(Product.class), params);
	}

}

显示商品

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>








	
			

		

			
商品编号
			
商品名称
			
市场价
			
商城价
			
商品图片
			
上市日期
			
商品描述
		
		

				
${p.pid }
				
${p.pname }
				
${p.market_price }
				
${p.shop_price }
				

					 
				
				
${p.pdate }
				
${p.pdesc }
			
		
	
	<%@ include file="/pageFile.jsp" %>

product_list.jsp包含pageFile.jsp（<%@ include file="/pageFile.jsp" %>）

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

	当前第${page.currentPageNum}页/一共${page.totalPageNum}页/ 首页 上一页
	
		${pagenum}
	

	下一页
	末页
	
	

pageFile.jsp运行效果

整体效果