How to specify a file path in java code to run on Unix machine?

Question

Hi
I have a problem when running my project Swing on Unix machine.
In my code, the user will press a button and then the program will look for the file "ReadMe" in the folder "Documentation" , and reads the content of this file. My code is "Documentation\\ReadMe" and it works well on PC. (The folder "Documentation" is in the same directory with my Java code).
But when I try on Unix, the program can not read the file. It can only read the file "ReadMe" if I take this file and put it in the same directory with my Java code ( this means not through another folder). So how can we make it read the file in a folder ? It seems that "Documentation\\ReadMe" does not work in Unix, or the symbol "\\" does not work.
I would be thankful if anybody can help me with this.
Thank you very much

Answer 1

You really shouldn't use any path method, as neither are very consistant or platform independent. The JVM provides a way to grab resources from the classpath. These resources can be any data at all, in fact, it's how java itself locates classes. Here's an example how you would do this in a non-static method.
public URL getReadMe() {
  // In this context the forward slash is universal
  String docDirectory = "Documentation/"
  // We have to use the classloader to grab the resource
  ClassLoader cl = this.getClass().getClassLoader();
  // Next we get the resource 
  URL readMeURL = cl.getResource(docDirectory + "ReadMe");
  return readMeURL;
}The URL can be used in whatever way you need to get the information out of the resource. If it was an image you might use the "Toolkit" to make an image object out of it. The great thing about this method is it will work even if your loading the program out of a Jar file. The resource paths start at the top of the classpath, just like classes.