Unable to write log file using Log4j on Google App Engine

Question

I am trying log4j. I got output for printing in console. But when I try using FileAppender it shows error. I am using google app engine. This is my code.

package com.log4jtest;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.http.*;

import org.apache.log4j.Appender;
import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.FileAppender;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.SimpleLayout;

@SuppressWarnings("serial")
public class Log4jTestServlet extends HttpServlet  
{

  int count=0;
  private static Logger log=Logger.getLogger(Log4jTestServlet.class);
  public void doGet(HttpServletRequest req, HttpServletResponse resp)throws      IOException 
  {
     resp.setContentType("text/plain");

    /*BasicConfigurator.configure();*/
    Appender app=new FileAppender(new SimpleLayout(),"hello.log");
    log.setLevel(Level.TRACE);
    BasicConfigurator.configure(app);
    PrintWriter out=resp.getWriter();

    //private static Logger log=Logger.getLogger(Log4jTestServlet.class);
    String username="faisal";
    String password="mohamed";

    //int count=0;

    count++;
    out.println(count);
    log.trace("TRACE");
    log.debug("DEBUG");
    log.info("INFO");
    log.warn("WARN");
    log.error("ERROR");
    log.fatal("FATAl");


    System.out.println("end line of the program");
    resp.getWriter().println("Hello, world");
  }
 }

And this is my error..

Http error 500
 java.io.FileOutputStream is a restricted class. Please see the Google  App Engine developer's guide for more details.

now what I have to do

Answer 1

See answer to this: Does Google App Engine allow creation of files and folders on the server? You cannot write files on GAE. Use console or Log API.