jsp假分页示例

我不是女神ヾ 2022-08-12 01:25 122阅读 0赞

在web开发过程中，不可避免的需要使用到分页的功能，jsp分页一般有真分页和假分页。例如mysql：真分页意思就是用limit查询语句从后台检索出结果集传回jsp页面显示。而假分页则是后台传回所有数据的list集合或者结果集，利用js或者游标等进行分页。（假分页一定程度上给服务器运行增加了压力）  
      下面示例是 利用后台保存到session的一个list集合进行假分页的案例  
  
<%@ page language="java" import="java.util.\*,com.entity.\*;" pageEncoding="UTF-8"%>  
<%  
String path = request.getContextPath();  
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";  
%>  
  
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "[http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd][http_www.w3.org_TR_xhtml1_DTD_xhtml1-transitional.dtd]">  
<html xmlns="[http://www.w3.org/1999/xhtml][http_www.w3.org_1999_xhtml]">  
<head>  
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />  
<title>无标题文档</title>  
</head>  
  
<body>  
<%  
List<User> data=(List<User>)session.getAttribute("user");  
  
int totalNum=data.size();  
  
int pageSize=1;  
  
int currentPage=1;  
  
String num=request.getParameter("page");  
if(num!=null)\{  
currentPage=Integer.parseInt(num);  
\}  
if(currentPage<1)\{  
currentPage=1;  
\}  
  
int totalPage=totalNum/pageSize;  
if(totalNum%pageSize!=0)\{  
totalPage++;  
\}  
if(currentPage>totalPage)\{  
currentPage=totalPage;  
\}  
  
int startNum=(currentPage-1)\*pageSize;  
int endNum=currentPage\*pageSize-1;  
  
if(endNum>=data.size())\{  
endNum=data.size()-1;  
\}  
%>  
  
  
  
<table>  
<tr>  
   <td>firstName</td><td>lastName</td><td>email</td><td></td><td></td>  
</tr>  
     <%for(int i=startNum;i<=endNum;i++)\{%>  
     <%  
           User p=(User)data.get(i);  
     %>  
    <tr>  
        <td><%=p.getFirstName()%></td>  
        <td><%=p.getLastName()%></td>  
        <td><%=p.getEmail()%></td>  
        <td></td>  
        <td></td>  
    </tr>  
     <%\}%>  
  
<tr>  
    <td>当前页:<%=currentPage%>/总共页:<%=totalPage%></td>  
    <td><a href="user/JSP假分页.jsp?page=1">首页</a></td>  
    <td><a href="user/JSP假分页.jsp?page=<%=currentPage-1%>">上一页</a></td>  
    <td><a href="user/JSP假分页.jsp?page=<%=currentPage+1%>">下一页</a></td>  
    <td><a href="user/JSP假分页.jsp?page=<%=totalPage%>">尾页</a><br/></td>  
</tr>                                                
</table>  
</body>  
</html>

[http_www.w3.org_TR_xhtml1_DTD_xhtml1-transitional.dtd]: http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd
[http_www.w3.org_1999_xhtml]: http://www.w3.org/1999/xhtml