package com.bitmechanic.listlib;import java.util.Enumeration;import javax.servlet.http.HttpServletRequest;import javax.servlet.jsp.PageContext;import javax.servlet.jsp.JspException;import javax.servlet.jsp.tagext.TagSupport;public class PrevLinkTag extends ListBaseTag {    protected String getURL(int offset) {        HttpServletRequest req = (HttpServletRequest)pageContext.getRequest();        StringBuffer url = new StringBuffer(req.getRequestURI());        boolean first = true;        for (Enumeration e = req.getParameterNames(); e.hasMoreElements();) {            String name = (String)e.nextElement();            if (!name.equals(InitTag.OFFSET_KEY)) {                if (first) {                    url.append("?");                    first = false;                }                else url.append("&");                                url.append(name).append("=");                url.append(java.net.URLEncoder.encode(req.getParameter(name)));            }        }        if (first)            url.append("?");        else            url.append("&");        url.append(InitTag.OFFSET_KEY).append("=").append(offset);        return url.toString();    }    public int doStartTag() throws JspException {        ListContainer lc = getList();        int offset = Math.max(0, lc.getStart() - lc.getMax() - 1);        print(getURL(offset));        return SKIP_BODY;    }    }