SpringMvc+Maven框架下简单分页实现

分页是开发中最基本但必不可少的部分，之前在学校也没有那么多数据，一直以来对分页也没怎么重视，都是用别人现成的，最近自己尝试着写了个分页模块，顺便记录下方便之后使用。具体实现主要从以下几个部分实现：

1.分页实体类

首先我们需要一个工具类，如下内容所示：

package com.cn.hnust.pojo;import java.io.Serializable;/*** 分页*/public class Page implements Serializable {private static final long serialVersionUID = -3198048449643774660L;private int pageNow = 1; // 当前页数private int pageSize = 4; // 每页显示记录的条数private int totalCount; // 总的记录条数private int totalPageCount; // 总的页数@SuppressWarnings("unused")private int startPos; // 开始位置，从0开始@SuppressWarnings("unused")private boolean hasFirst;// 是否有首页@SuppressWarnings("unused")private boolean hasPre;// 是否有前一页@SuppressWarnings("unused")private boolean hasNext;// 是否有下一页@SuppressWarnings("unused")private boolean hasLast;// 是否有最后一页/*** 通过构造函数 传入  总记录数  和  当前页* @param totalCount* @param pageNow*/public Page(int totalCount, int pageNow) {this.totalCount = totalCount;this.pageNow = pageNow;}/*** 取得总页数，总页数=总记录数/总页数* @return*/public int getTotalPageCount() {totalPageCount = getTotalCount() / getPageSize();return (totalCount % pageSize == 0) ? totalPageCount: totalPageCount + 1;}public void setTotalPageCount(int totalPageCount) {this.totalPageCount = totalPageCount;}public int getPageNow() {return pageNow;}public void setPageNow(int pageNow) {this.pageNow = pageNow;}public int getPageSize() {return pageSize;}public void setPageSize(int pageSize) {this.pageSize = pageSize;}public int getTotalCount() {return totalCount;}public void setTotalCount(int totalCount) {this.totalCount = totalCount;}/*** 取得选择记录的初始位置* @return*/public int getStartPos() {return (pageNow - 1) * pageSize;}public void setStartPos(int startPos) {this.startPos = startPos;}/*** 是否是第一页* @return*/public boolean isHasFirst() {return (pageNow == 1) ? false : true;}public void setHasFirst(boolean hasFirst) {this.hasFirst = hasFirst;}/*** 是否有首页* @return*/public boolean isHasPre() {// 如果有首页就有前一页，因为有首页就不是第一页return isHasFirst() ? true : false;}public void setHasPre(boolean hasPre) {this.hasPre = hasPre;}/*** 是否有下一页* @return*/public boolean isHasNext() {// 如果有尾页就有下一页，因为有尾页表明不是最后一页return isHasLast() ? true : false;}public void setHasNext(boolean hasNext) {this.hasNext = hasNext;}/*** 是否有尾页* @return*/public boolean isHasLast() {// 如果不是最后一页就有尾页return (pageNow == getTotalCount()) ? false : true;}public void setHasLast(boolean hasLast) {this.hasLast = hasLast;}}

2.Mybatis xml 文件配置

在有了上述分页实体之后，接下来就需要在Mybatis XXmapper.xml文件中配置查询语句，具体思路是：
a. 查询出所有符合条件的结果总数
b.将查到的结果总数通过分页实体的构造函数传入，然后计算出分页参数
c.根据分页参数查询结果集返回

• 查询所有符合条件的记录条数

 <select id="getCounts" resultType="int" parameterType="java.util.Map">    SELECT COUNT(*) FROM book    WHERE XX=查询条件  </select>

• 根据分页参数查询符合条件的list

<select id="getBookByPage" resultMap="BaseResultMap">    select    <include refid="Base_Column_List" />    ,    <include refid="Blob_Column_List" />    from book WHERE (1=1    <include refid="bookParams" />  这里自己的查询条件)    order by Id DESC     limit #{startPos--起始下标},#{pageSize--每页数量}   </select> 

3.Controller –Service–Dao 层调用代码

• Controller 层代码

@RequestMapping("/getBookByPage")    public String getBookByPage(HttpServletRequest request, Model model,Book book, HttpSession session, Type type, Subtype sub) {        List<Book> bookList = new ArrayList<Book>();        int counts;// 分页记录总数        String pageNow = request.getParameter("pageNow");        String countString = request.getParameter("allcount");        Page page = null;        // 判断分页参数        Book bookParams = (Book) session.getAttribute("bookParams");        if (countString != null) {            counts = Integer.parseInt(countString);            book = bookParams;        } else {            counts = bookService.getCounts(book);        }        // 添加查询条件id name author publish type subtype        // System.out.println(book.getName() + "|" + book.getAuthor() + "|"        // + book.getPublish() + "|" + book.getType() + "|"        // + book.getSubtype());        Map<String, Object> condition = new HashMap<String, Object>();        condition.put("id", book.getId());        condition.put("name", book.getName());        condition.put("publish", book.getPublish());        condition.put("type", book.getType());        condition.put("subtype", book.getSubtype());        if (pageNow != null && pageNow != "") {            page = new Page(counts, Integer.parseInt(pageNow));        } else {            page = new Page(counts, 1);        }        condition.put("startPos", page.getStartPos());        condition.put("pageSize", page.getPageSize());        bookList = this.bookService.getBookByPage(condition);        // System.out.println("list.size():" + bookList.size());        model.addAttribute("bookList", bookList);        model.addAttribute("page", page);        model.addAttribute("bookParams", book);        session.setAttribute("bookParams", book);        model.addAttribute("url", "/book/getBookByPage");        // 下面判断是否从删除页面跳转过来        String deleted = (String) session.getAttribute("bookDeleted");        // System.out.println(deleted);        if (deleted != null) {            model.addAttribute("bookDeleted", deleted);            session.removeAttribute("bookDeleted");        }        model.addAttribute("subList", subList);        return "book/list";    }

• Service 层代码

@Resource    private BookDao bookDao;    public int getCounts(Book book) {        // TODO Auto-generated method stub        return bookDao.getCounts(book);    }    public List<Book> getBookByPage(Map condition) {        // TODO Auto-generated method stub        return bookDao.getBookByPage(condition);    }

• Dao 层代码

 int getCounts(Book book); List <Book>  getBookByPage(Map condition);

4.前端jsp页面代码

前端页面page,公用jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%><form action='<c:url value="${url}"></c:url>' method="post" id="pageTurnForm"><c:if test="${page != null && page.totalPageCount >= 1}"><tr ><td colspan="11"><div class="fr" style="margin-bottom:10px;">  <button type="button"  id="sub" class="btn btn-default" onclick="javascript:jumpToPage();"  style="float:right">跳转<!-- 跳转 --></button>    <input type="text" id="jump" class="form-control input-mini input-inline  " maxlenght="5" style=" float:right;text-align:center; margin: 0px 6px 0px 0px;">    <div class="btn-group" style="float:right">        <c:choose>               <c:when test="${page.pageNow == 1}">                <button type="button" class="btn btn-default"  disabled="disabled">&nbsp;<i class="fa  fa-angle-double-left"></i></button>             </c:when>                  <c:otherwise>            <button type="button" class="btn btn-default" onclick="javascript:prevousPage();">&nbsp;<i class="fa  fa-angle-double-left"></i></button>            </c:otherwise>          </c:choose>        <button type="button" class="btn btn-default" disabled="disabled" onclick="javascript:jumpToPage();">第 ${page.pageNow} / ${page.totalPageCount}  页</button>                <c:choose>               <c:when test="${page.pageNow == page.totalPageCount}">                <button type="button" class="btn btn-default"  disabled="disabled" >&nbsp;<i class="fa  fa-angle-double-right"></i></button>             </c:when>                  <c:otherwise>                <button type="button" class="btn btn-default" onclick="javascript:nextPage();">&nbsp;<i class="fa  fa-angle-double-right"></i></button>            </c:otherwise>          </c:choose>    </div></div></td></tr></c:if>        <c:if test="${page == null || page.totalCount == 0}">        <tr>            <td colspan="11" class="alert-danger"><i class="fa fa-info-circle"></i> 无相关查询结果！        </tr>        </c:if>        <input type="hidden" id="pageNow" name="pageNow"/>        <input type="hidden" id="allcount" name="allcount" value="${page.totalCount}"/>        </form>        <script type="text/javascript">        function jumpToPage(){            var jump=$("#jump").val();            var pageNow=${page.pageNow};            var pageTotal=${page.totalPageCount};                if(jump==""||jump>pageTotal||jump<1||isNaN(jump)){                    showAlertModel("提示信息","请输入正确的页码！",null);                    return false;                }else{                    $("#pageNow").val(jump);                    $("#pageTurnForm").submit();                }        }        function nextPage(){            var pageNow=${page.pageNow};            var pageTotal=${page.totalCount};            $("#pageNow").val(parseInt(pageNow)+1);            $("#pageTurnForm").submit();        }        function prevousPage(){            var pageNow=${page.pageNow};            var pageTotal=${page.totalCount};            $("#pageNow").val(parseInt(pageNow)-1);            $("#pageTurnForm").submit();        }        /*处理回车事件*/        jQuery(document).ready(function() {            $("#jump").keydown(function(event){                if(event.keyCode == 13){                    $("#sub").click();                    return false;                }else{                }            });        });        </script>

至此，分页功能已经完成，效果图如下：