Need to determine location of main class

Question

I want to be able to run a Java program that accesses files somewhere relative to the file that contains its main class. I want the program to be able to access these files no matter what directory the user executes it from. The user can run the program from any location, so I can't just look at the current working directory.
My first attempt at a solution was to use a configuration file in the user's home directory that tells the program where to look for the other files it needs, but this solution has met with some resistance. I would like to be able to determine the program file's path from within the program. Is this possible?
andy

Answer 1

Rather than trying to find the main class' absolute path, use Class.getResource or Class.getResourceAsStream to find something that's in your classpath.
Let's say you have the following: C:\classes\com\foo\Bar.class
C:\classes\config\cfg.cfg[
java -cp C:\classes com.foo.BarThen you'd do something like this: class Bar {
... main(...) {
        InputStream in = Bar.class.getResourceAsStream("config/cfg.cfg");
        // read and process input stream
}All you need is to know where cfg.cfg is relative to some classpath element. You don't need to know which element, just that its in /config/cfg.cfg relative to one of the jars or dirs in your classpath.