jsp分页

我是一个初级入门者，刚自己琢磨了一个分页的。大家帮我看看，我的思路和代码哪有问题
<%

int ipage=20; //分页单位
int allpage;  //总页数
int pages;    //接受的页码变量
int cpage=1;  //当前页
int spage;
    int id =Integer.parseInt(request.getParameter("auctionsInfoId"));
    Integer Num = PageSQL.count(id);
   
     //获得总页面数
allpage = (int)Math.ceil((Num + ipage-1) / ipage);

//判断参数pages是否为空
if (request.getParameter("pages")==null) {
pages=1;
} else {
pages = new Integer(request.getParameter("pages")).intValue();
}
out.print("<script>alert("+pages+")</script>");
//判断当前页
if(pages > allpage ){ // pages == 0
cpage = 1;
} else {
cpage = pages;
}

//判断起始页
spage=(cpage-1)*ipage;
        
         %> 

      <%
if(pages > 1 && request.getParameter("pages") != null){
      %>
<li><a href="http://localhost:8080/website/Auctions/auctionshistory.jsp?auctionsInfoId=133&pages=<%= pages-1 %>" >
            <span>上一页</span>
            </a></li>
      <%
        }
if(pages >= 5 && request.getParameter("pages") != null ){
      for(int j = pages - 3 ; j < pages + 2 && j < allpage; j++) {
       %>
            test
            <li><a href="http://localhost:8080/website/Auctions/auctionshistory.jsp?auctionsInfoId=133&pages=<%= j +1 %>">
            <span><%= j +1 %></span>
            </a></li>
       <%       
       }}else {
       for(int h = 0 ; h < 5 && h < allpage; h++) {
       %>

<li><a href="http://localhost:8080/website/Auctions/auctionshistory.jsp?auctionsInfoId=133&pages=<%= h +1 %>">
            <span><%= h +1 %></span>
            </a></li>

<%       
       }}
       if(pages != allpage){
       %>
        <li><a href="http://localhost:8080/website/Auctions/auctionshistory.jsp?auctionsInfoId=133&pages=<%= pages+1 %>">
            <span>下一页</span>
            </a></li>
       <%       
       }
       %>