/**
 * Trampolin, forward requests to a different URL.
 * <BR/>
 * To find <B>outgoing</B> links from your website in your access.log,
 * replace all outgoing links:
 * <PRE>
 *     http://foreignlink
 * </PRE>
 * by something like
 * <PRE>
 *     http://installedTrampolin?http://foreignlink
 * </PRE>
 * It's so simple.
 */
package de.spieleck.servlets;

import java.io.IOException;
import javax.servlet.*;
import javax.servlet.http.*;

public class Trampolin
    extends HttpServlet
{
    protected String prefix;

    public void init()
	throws ServletException
    {
        prefix = getInitParameter("prefix");
        if ( prefix == null )
            prefix = "";
        System.err.println("FSN Trampolin: prefix='"+prefix+"'");
    }

    public void service(HttpServletRequest req, HttpServletResponse res) 
	throws ServletException, IOException
    {
	String path = req.getQueryString();
        if ( path == null )
	{
	    res.sendError( HttpServletResponse.SC_BAD_REQUEST );
	    return;
	}
        res.sendRedirect(prefix+path);
    }
}