大数据分页功能的一种实现方式

怼烎@ 2022-06-14 23:43 129阅读 0赞

# 大数据分页功能 的一种实现方式 #

## 工具类 Page.java ##

> **功能: 界面上所有与分页有关的都找此类要**

import java.util.List;
    
    //界面上所有与分页有关的都找此类要
    public class Page { 
        private List records;
        private int pagesize = 10;//每页显示的记录条数
        private int pagenum;//用户要看的页码即当前页码
        private int totalpage;//总页数
        private int startIndex;//每页开始记录的索引
        private int totalrecords;//总记录条数
    
        //显示的页码
        private int startPage;
        private int endPage;
    
        //查询数据时的Servlet的URL
        private String servletUrl;
    
        public Page(int pagenum,int totalrecords){
            this.pagenum = pagenum;
            this.totalrecords = totalrecords;
    
            //计算每页开始记录的索引
            startIndex = (pagenum-1)*pagesize;
            //计算总页数
            totalpage = totalrecords%pagesize==0?totalrecords/pagesize:(totalrecords/pagesize+1);
    
            //显示的页码
            if(totalpage<=9){
                startPage = 1;
                endPage = totalpage;
            }else{
                startPage = pagenum-4;
                endPage = pagenum+4;
                if(startPage<1){
                    startPage = 1;
                    endPage = 9;
                }
                if(endPage>totalpage){
                    endPage = totalpage;
                    startPage = totalpage-8;
                }
            }
        }
    
    
        public List getRecords() {
            return records;
        }
        public void setRecords(List records) {
            this.records = records;
        }
        public int getPagesize() {
            return pagesize;
        }
        public void setPagesize(int pagesize) {
            this.pagesize = pagesize;
        }
        public int getPagenum() {
            return pagenum;
        }
        public void setPagenum(int pagenum) {
            this.pagenum = pagenum;
        }
        public int getTotalpage() {
            return totalpage;
        }
        public void setTotalpage(int totalpage) {
            this.totalpage = totalpage;
        }
        public int getStartIndex() {
            return startIndex;
        }
        public void setStartIndex(int startIndex) {
            this.startIndex = startIndex;
        }
        public int getTotalrecords() {
            return totalrecords;
        }
        public void setTotalrecords(int totalrecords) {
            this.totalrecords = totalrecords;
        }
    
    
        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 String getServletUrl() {
            return servletUrl;
        }
    
    
        public void setServletUrl(String servletUrl) {
            this.servletUrl = servletUrl;
        }
    
    }

## jsp页面使用 ##

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    
                    第${page.pagenum}页/共${page.totalpage}页  
                    <a href="${pageContext.request.contextPath}/servlet/ShowAllCustomersServlet">首页</a>  
                    <a href="${pageContext.request.contextPath}/servlet/ShowAllCustomersServlet?pagenum=${page.pagenum-1==0?1:page.pagenum-1}">上一页</a>  
                    <c:forEach begin="${page.startPage}" end="${page.endPage}" var="num">
                        <a href="${pageContext.request.contextPath}/servlet/ShowAllCustomersServlet?pagenum=${num}">${num }</a>
                    </c:forEach>
                      
                    <a href="${pageContext.request.contextPath}/servlet/ShowAllCustomersServlet?pagenum=${page.pagenum+1>page.totalpage?page.totalpage:page.pagenum+1}">下一页</a>  
                    <a href="${pageContext.request.contextPath}/servlet/ShowAllCustomersServlet?pagenum=${page.totalpage}">尾页</a>
                    <select id="s1">
                        <c:forEach begin="1" end="${page.totalpage}" var="num">
                            <option value="${num}" ${ page.pagenum==num?'selected="selected"':''}>${num}</option>
                        </c:forEach>
                    </select>
                    <a href="javascript:jump()">跳转</a>
                    <script type="text/javascript"> function jump(){ var num = document.getElementById("s1").value; window.location.href="${pageContext.request.contextPath}/servlet/ShowAllCustomersServlet?pagenum="+num; } </script>