package com.acme.tag;

import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import javax.servlet.http.*;
import java.util.*;
import java.net.*;

/**
 * A Tag for checking last modification date of the current JSP
 * @author Magnus Rydin
 */
public class LastModifiedTag extends TagSupport
{
  private Locale locale;
  private HttpServletRequest request;

  /**
   * Constructor
   */
  public LastModifiedTag()
  {
    super();
  }

  /**
   * Method used by the JSP container to set the Locale to use.
   */
  public void setLocale(Locale locale)
  {
    this.locale=locale;
  }

  /**
   * Method Called at end of Tag
   * @return either EVAL_PAGE or SKIP_PAGE
   */
  public int doEndTag() throws javax.servlet.jsp.JspTagException
  {
    try{
      //get the request
      request= (HttpServletRequest) pageContext.getRequest();
      if(locale==null){
        //if no Locale was given, use the Locale set by the user
        locale=request.getLocale();
      }
      if(locale==null){
        //if no Locale was set by the user, use system default
        locale=Locale.getDefault();
      }
      //obtain the resource from the ServletContext
      URL url=pageContext.getServletContext().getResource(request.getServletPath());
      //read the lastModified value. Need to check for file due to a bugg in Suns VM
      long miliseconds;
      if(url.getProtocol().equals("file")){
        miliseconds=new java.io.File(url.getFile()).lastModified() ;
      }else{
        miliseconds=url.openConnection().getLastModified();
      }
      //create a date out of the long if greater than 0
      if(miliseconds>0){
        //long miliseconds=(url.getProtocol().equals("file") ? new java.io.File(url.getFile()).lastModified() : url.openConnection().getLastModified());

        Date lastModified=new Date(miliseconds);
        //write the date using the Locale to format.
        pageContext.getOut().write(java.text.DateFormat.getDateTimeInstance(java.text.DateFormat.SHORT, java.text.DateFormat.SHORT,locale).format(lastModified));
      }
    }catch(java.net.MalformedURLException mue){
      throw new JspTagException(mue.getMessage());
    }catch(java.io.IOException ioe){
      throw new JspTagException(ioe.getMessage());
    }catch(java.lang.NullPointerException npe){
      //do nothing
    }

    return EVAL_PAGE;
  }
}