java.io.File bug in Linux?

Newbie & Debugging Questions
#1

I made a very simple runnable jar with the following code:

package stuff;

import java.io.File;
import javax.swing.JOptionPane;

public class Testing 
{
	public static void main(String[] args)
	{	
		File file = new File("");
		JOptionPane.showMessageDialog(null, file.getAbsoluteFile());
	}
}

Placing this jar in example C:/Test/Hello and running it will cause the program to print C:/Test/Hello, which is absolutely correct.
Doing the same, but in Linux, and the program will print /home/pj1 no matter where the jar is located. This is wrong! It should print the path to its location.
Is there a way to fix this?