servlet+mvc实现分页显示列表页

实现分页显示有好多种方法，有客户端显示的用JS，有服务端分页的。在此我对服务端的分页功能进行叙述
先展示下我的项目的目录结构：

标准的MVC模式，现在我的分页步骤是从jsp调用servlet，通过servlet调用对应的service类，service类去调用dao类
1、先看下页面中的调用方式：

<div>当前${requestScope.pageBean.currentPage}/${requestScope.pageBean.totalPage }页
    <a href="${pageContext.request.contextPath}/SenInfoManagerServlet?method=showSenInfo¤tPage=1">首页a>
    <a href="${pageContext.request.contextPath }/SenInfoManagerServlet?method=showSenInfo¤tPage=${requestScope.pageBean.currentPage-1}">上一页a>
    <a href="${pageContext.request.contextPath }/SenInfoManagerServlet?method=showSenInfo¤tPage=${requestScope.pageBean.currentPage+1}">下一页a>
    <a href="${pageContext.request.contextPath }/SenInfoManagerServlet?method=showSenInfo¤tPage=${requestScope.pageBean.totalPage}">尾页a>
    div>

定义了当前页，首页，上一页，下一页，尾页等方式。通过调用对应的servlet及currentPage，totalPage等参数，传递对应的pageBean数据
2、再看下servlet调用时的代码：

private void showSenInfo(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{

        try {
            String currPage = request.getParameter("currentPage");
            if(currPage == null || "".equals(currPage.trim())) {
                currPage = "1"; //第一次访问，设置当前页为1
            }
            int currentPage = Integer.parseInt(currPage);
            PageBean pageBean = new PageBean();
            pageBean.setCurrentPage(currentPage);

            List pageData = senInfoService.getAllSenInfo(pageBean);
            request.setAttribute("senInfoList",pageData);
            request.setAttribute("pageBean", pageBean);

            uri = request.getRequestDispatcher("/manager/senInfoManager.jsp");
            WebUtils.goTo(request,response,uri);
        }catch(Exception e) {
            LogUtils.getLogger(SenInfoManagerServlet.class.getName(), "error", e.toString());
        }
    }

此方法获取当前页参数，其中对应的PageBean类是我定义的翻页的Model类，下面看PageBean对应的设计代码：

public class PageBean {

    private int currentPage = 1; //当前页，默认显示第一页
    private int pageCount = 10; //每页显示的行数（查询返回的行数）
    private int totalCount;  //总记录数
    private int totalPage;  //总页数= 总记录数/每页显示的行数(+1)
    private List pageData; // 分页查询到的数据

    public int getCurrentPage() {
        return currentPage;
    }
    public void setCurrentPage(int currentPage) {
        this.currentPage = currentPage;
    }
    public int getPageCount() {
        return pageCount;
    }
    public void setPageCount(int pageCount) {
        this.pageCount = pageCount;
    }
    public int getTotalCount() {
        return totalCount;
    }
    public void setTotalCount(int totalCount) {
        this.totalCount = totalCount;
    }
    public int getTotalPage() {
        if(totalCount % pageCount == 0) {
            totalPage = totalCount / pageCount;
        }else {
            totalPage = totalCount / pageCount +1;
        }
        return totalPage;
    }
    public void setTotalPage(int totalPage) {
        this.totalPage = totalPage;
    }
    public List getPageData() {
        return pageData;
    }
    public void setPageData(List pageData) {
        this.pageData = pageData;
    }

}

在此分页类中设置了当前页currentPage，每页显示的总行数pageCount，总记录数totalCount，分页查询到的数据列表。
3、通过service调用dao类不再展示，其中service类没做其他任何操作，直接调用的dao类，现在看看dao类的设计代码：
先获取总数目：

/**
     * 获取总数目
     */
    @Override
    public int getTotalCount() {
        StringBuilder sb = new StringBuilder();
        sb.append(" SELECT");
        sb.append(" count(*) ");
        sb.append(" FROM ");
        sb.append(" senInfo");
        try {
            Long count = qr.query(sb.toString(), new 
                    ScalarHandler());
            return count.intValue();
        }catch(Exception e) {
            LogUtils.getLogger(SenInfoDao.class.getName(), "error", e.toString());
        }
        return 0;
    }

再获取每页对应的数据：

QueryRunner qr = DBUtils.getQueryRunner();

    @Override
    public List getAllSenInfo(PageBean pageBean) {
        int totalCount = this.getTotalCount();
        pageBean.setTotalCount(totalCount);

        if(pageBean.getCurrentPage() <= 0) {
            pageBean.setCurrentPage(1);
        }else if(pageBean.getCurrentPage() > pageBean.getTotalPage()) {
            pageBean.setCurrentPage(pageBean.getTotalPage());
        }
        //获取当前页：计算查询的起始行，返回的行数
        int currentPage = pageBean.getCurrentPage();
        int index = (currentPage - 1) * pageBean.getPageCount(); //查询起始行
        int count = pageBean.getPageCount(); //每页显示的行数

        List