title: FileNotFoundException after exporting as .jar file
body: <p>I'm using Eclipse and developing a java application where I use of a local file.
  The file is inside the project folder, in a subfolder, say "mydata/myfile.txt"
  When I run the app from eclipse everything works fine, I open a FileInputStream passing "mydata/myfile.txt" as the name and the file is read just fine.
  But when I export my application as .jar, and try to run it, all I get is a FileNotFoundException in the console.</p>
  
  <p>How can I export the program so that it can run on any computer and be able to access the file?
  Thank you in advance.</p>