Goods:图书模块按分类查询各层实现

//获取当前页码值
private int getPc(HttpServletRequest req)
{
int pc=1;
String param=req.getParameter("pc");
if(param!=null&&!param.trim().isEmpty())
{
try{
pc=Integer.parseInt(param);
}catch(RuntimeException e){}
}
return pc;
}

//获取url  截取url 页面中的分页导航中使用它作为超链接的目标  还带了条件 保证条件不丢
private String getUrl(HttpServletRequest req)
{    //http://localhost:8080//goods/BookServlet
//getRequestURI()获取/goods/BookServlet
//req.getQueryString()获取method=findByCategory&cid=xxx
String url=req.getRequestURI()+"?"+req.getQueryString();
//如果url中存在pc参数 截取掉 如果不存在则不用截取
int index=url.lastIndexOf("&pc=");
if(index!=-1)
{
url=url.substring(0,index);
}
return url;
}

public String findByCategory(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {

//得到pc 如果页面传递使用页面的 如果没传pc=1
int pc=getPc(req);

//2得到url
String url=getUrl(req);
//3获取查询条件 本方法是cid 即分类id
String cid=req.getParameter("cid");

//使用pc cid 调用service
PageBean<Book> pb=bookService.findByCategory(cid,pc);
//使用pageBean设置url 保存pageBean 转发到/jsps/book/list.jsp页面
pb.setUrl(url);
req.setAttribute("pb", pb);
return "f:/jsps/book/list.jsp";

}

<ul>
<c:forEach items="${pb.beanList}" var="book">
<li>
<div class="inner">
<a class="pic" href="<c:url value='/jsps/book/desc.jsp'/>"><img
src="<c:url value='/${book.image_b }'/>" border="0" /> </a>
<p class="price">
<span class="price_n">¥${book.currPrice}</span>
<span class="price_r">¥${book.price}</span>
(<span class="price_s">${book.discount}折</span>)
</p>
<p>
<a id="bookname"
title="${book.bname }"
href="<c:url value='/jsps/book/desc.jsp'/>">${book.bname }</a>
</p>
<p>
<a href="<c:url value='/jsps/book/list.jsp'/>" name='P_zz'
title='Craig Walls'>${book.author }</a>
</p>
<p class="publishing">
<span>出 版 社：</span><a href="<c:url value='/jsps/book/list.jsp'/>">${book.press} }</a>
</p>
<p class="publishing_time">
<span>出版时间：</span>${book.publishtime}
</p>
</div></li>
</c:forEach>

</ul>