Works as an application but not an applet

Question

I have a swing program that works perftectly fine if ran from the command prompt as an application, but once it is run as an applet through a browser some parts are not working. i have narrowed it down to the following lines of code that are the culprits through troubleshooting:
public static void writeServers(LinkedList serverList) {
     String filename = "C:/jdk/TS2/serverlist.dat";
     try {
          FileOutputStream fout = new FileOutputStream(filename);
     catch(IOException e) {}          
Apparently it doesn't want to create the FileOutputStream, even though this works fine if the program is run as an application. Does anyone know why this isn't working as an applet but works fine as an application?

Answer 1

Ok, here is what I've got:
public static void writeConfig(Config configuration, ClassLoader cl) {
String filename = (cl.getResource("configuration.dat")).toString();
filename = filename.substring(6);
try {
FileOutputStream fout = new FileOutputStream(filename);
ObjectOutputStream oout = new ObjectOutputStream(fout);
oout.writeObject(configuration);
oout.close();
catch(IOException e) { }
And both this file and the configuration.dat are in a jar file that is signed, however it will still not write the configuration.dat file. It will read it with no problem. But no writing.