分页复用代码【Page类、JSP显示页面】

前言

为了复用，记载一些以前写过的工具类、方法

page类

    import java.util.List;

    /**
     * Created by ozc on 2017/3/1.
     */
    public class Page {

        //保存着分页的数据
        private List<Customer> list;

        //总记录数
        private long totalRecord;

        //每页显示记录数，这里我规定每页显示3条
        private int linesize = 3;

        //总页数
        private int totalPageCount;

        //当前显示的页数
        private int currentPageCount;

        //开始取的记录位置
        private int startIndex;

        //记录JSP页面开始的页数和结束的页数
        private int startPage;
        private int endPage;

        private String url;


        public Page() {
        }

        public Page(int currentPageCount, long totalRecord) {


            //将传递进来的currentPageCount初始化
            this.currentPageCount = currentPageCount;

            //总页数
            totalPageCount = (int) (totalRecord % linesize == 0 ? totalRecord / linesize : totalRecord / linesize + 1);

            this.totalRecord = totalRecord;

            //开始取数据的位置
            startIndex = (currentPageCount - 1) * linesize;


            //如果当前页小于10，那么开始页为1，结束页为10就行了
            if (this.currentPageCount <= 10) {
                this.startPage = 1;
                this.endPage = 10;
            } else {
                this.startPage = this.currentPageCount - 4;
                this.endPage = this.currentPageCount + 5;

                //加减后页数越界的情况
                if (startPage < 1) {
                    this.startPage = 1;
                    this.endPage = 10;
                }
                if (endPage > totalPageCount) {
                    this.startPage = this.currentPageCount - 9;
                    this.endPage = this.totalPageCount;
                }
            }

        }
        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }
        public int getStartIndex() {
            return startIndex;
        }
        public void setCurrentPageCount(int currentPageCount) {
            this.currentPageCount = currentPageCount;
        }
        public void setStartIndex(int startIndex) {
            this.startIndex = startIndex;
        }

        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 getTotalPageCount() {
            return totalPageCount;
        }

        public void setTotalPageCount(int totalPageCount) {
            this.totalPageCount = totalPageCount;
        }

        public List<Customer> getList() {
            return list;
        }

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

        public long getTotalRecord() {
            return totalRecord;
        }

        public void setTotalRecord(long totalRecord) {
            this.totalRecord = totalRecord;
        }

        public int getLinesize() {
            return linesize;
        }

        public void setLinesize(int linesize) {
            this.linesize = linesize;
        }


        public long getCurrentPageCount() {
            return currentPageCount;
        }

        public void setCurrentPageCount(long currentPageCount) {
            this.currentPageCount = (int) currentPageCount;
        }
    }

显示页面JSP

<%--
  Created by IntelliJ IDEA.
  User: ozc
  Date: 2017/3/1
  Time: 21:17
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%--显示当前页数--%>
当前页数是：[${page.currentPageCount}]&nbsp;&nbsp;&nbsp;

<%--如果当前的页码大于1，才显示上一步--%>
<c:if test="${page.currentPageCount>1}">

    <%--把传递过去的页码-1就行了--%>
    <a href="${page.url}?currentPageCount=${page.currentPageCount-1}">
        上一步
    </a>
</c:if>


<%--提供页数的界面--%>
<c:forEach var="pageNum" begin="${page.startPage}" end="${page.endPage}">
    <a href="${page.url}?currentPageCount=${pageNum}">
        [${pageNum}]&nbsp;
    </a>
</c:forEach>

<%--如果当前的页码小于总页数，才显示下一步--%>
<c:if test="${page.currentPageCount<page.totalPageCount}">

    <%--把传递过去的页码-1就行了--%>
    <a href="${page.url}?currentPageCount=${page.currentPageCount+1}">
        下一步
    </a>&nbsp;&nbsp;
</c:if>

<input type="text" id="currentPageCount">
<input type="button" value="跳转" onclick="goPage()">

总页数是：${page.totalPageCount}&nbsp;&nbsp;

总记录数是：${page.totalRecord}


<script type="text/javascript">

    /*既然写上了JavaScript代码了，就顺便验证输入框输入的数据是否合法吧*/
    function goPage() {

        /*获取输入框控件*/
        var input = document.getElementById("currentPageCount");

        /*获取输入框的数据*/
        var value = input.value;

        if(value==null || value==""){
            alert("请输入页码");
            return false;
        }

        if(!value.match("\d+")){
            alert("请输入数字");
            return false;
        }

        if(value<1 || value>${page.totalPageCount}){
            alert("请输入合法数据");
            return false ;
        }

        window.location.href="${page.url}?currentPageCount="+value;
    }

</script>