MySql 分页

package com.ctrl.vo; 2 3 public class Page { 4 private int totalPage;// 总页数 5 private int currentPage;// 当前页 6 private int totalRecord;// 总记录数 7 private int currentRecord=0;// 当前记录条数 8 private int pageSize = 10;// 每页默认记录数 9 10 public int getTotalPage() { 11 return totalPage; 12 } 13 14 public void setTotalPage(int totalRecord, int pageSize) { 15 if (totalRecord % pageSize == 0) 16 this.totalPage = totalRecord / pageSize; 17 else 18 this.totalPage = totalRecord / pageSize + 1; 19 } 20 21 public int getCurrentPage() { 22 return currentPage; 23 } 24 25 public void setCurrentPage(int currentRecord, int pageSize) { 26 if (currentRecord % pageSize == 0) 27 this.currentPage = currentRecord / pageSize; 28 else 29 this.currentPage = currentRecord / pageSize + 1; 30 } 31 32 public int getTotalRecord() { 33 return totalRecord; 34 } 35 36 public void setTotalRecord(int totalRecord) { 37 this.totalRecord = totalRecord; 38 } 39 40 public int getCurrentRecord() { 41 return currentRecord; 42 } 43 44 public void setCurrentRecord(int currentRecord) { 45 this.currentRecord = currentRecord; 46 } 47 48 @Override 49 public String toString() { 50 return "Page [totalPage=" + totalPage + ", currentPage=" + currentPage 51 + ", totalRecord=" + totalRecord + ", currentRecord=" 52 + currentRecord + ", pageSize=" + pageSize + "]"; 53 } 54 55 public int getPageSize() { 56 return pageSize; 57 } 58 59 public void setPageSize(int pageSize) { 60 this.pageSize = pageSize; 61 } 62 63 }

其次，showUsers.jsp页面（有省略，且部分名修改）

<c:choose>
            <c:when test="${users != null }">
                <br>
                <form action="#" method="post">
                    <table class="table table-striped table-bordered">
                        <thead>
                            <tr>
                                <td>ID</td>
                                <td>NAME</td>
                                <td>CODE</td>
                                <td>PWD</td>
                                <td>STATE</td>
                                <td>FLAG</td>
                                <td>Update</td>
                            </tr>
                        </thead>
                        <c:forEach items="${users }" var="user">
                            <tr>
                                <td>${user.id }</td>
                                <td>${user.name }</td>
                                <td>${user.code }</td>
                                <td>${user.pwd }</td>
                                <td>${user.state }</td>
                                <td>${user.flag }</td>
                                <td><a href="update.jsp?user=${user }">update</a></td>
                            </tr>
                        </c:forEach>
                    </table>
                </form>
                <c:if test="${flag==‘T‘}">
                    <a
                        href="<%=request.getContextPath()%>/showLimitUsers？currentRecord=${page.currentRecord}&type=prev">前一页</a>
                    /<a
                        href="<%=request.getContextPath()%>/showLimitUsers？currentRecord=${page.currentRecord}&type=next"> 后一页</a>
                </c:if>
.....

对于，servlet后台（SERVICE、DAO层代码省略...）

        Page page = new Page();
        UserService userService = new UserServiceImpl();
        //去掉管理员
        long totalRecord = userService.getUsersCount() - 1;
        page.setTotalRecord((int) totalRecord);
        page.setTotalPage(page.getTotalRecord(), page.getPageSize());
        String type = request.getParameter("type");
        if (request.getParameter("currentRecord") != null
                && !request.getParameter("currentRecord").equals("")) {
            int currentRecord = Integer.parseInt(request
                    .getParameter("currentRecord"));
            page.setCurrentRecord(currentRecord);
            page.setCurrentPage(page.getCurrentRecord(), page.getPageSize());
            if ("next".equals(type)
                    && page.getCurrentPage() < (page.getTotalPage() - 1)) {
                currentRecord = currentRecord + 10;
                page.setCurrentRecord(currentRecord);
            } else if ("prev".equals(type) && page.getCurrentPage() > 0) {
                currentRecord = currentRecord - 10;
                page.setCurrentRecord(currentRecord);
            }
        } else {
            page.setCurrentRecord(0);
        }
        List<User> users = userService.getLimitUsers(page.getCurrentRecord(),
                page.getPageSize());
        page.setCurrentPage(page.getCurrentRecord(), page.getPageSize());

        HttpSession session = request.getSession();
        //<a>标签是否显示
        session.setAttribute("flag", "T");
        session.setAttribute("users", users);
        session.setAttribute("page", page);

        response.sendRedirect(request.getContextPath() + "/showUsers.jsp");

当用户点击了next，当前记录数就加pageSize，prev则减去pageSize。同时当前页也需要与总页数之间进行比较，以防超越了页数范围。

由于未将所有功能均设置分页，故设定flag标志，当页面其他功能不需要分页的话，可以将分页<a>消除。

 

效果图：

PS：文中Page VO为借鉴而来。

心得：

　　分页不难，但还是会出现bug,需要好好调试。可以通过打印Page&将所传的值在input标签显示方便调试。

MySql 分页

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