File file = new File("filename.txt"); file = file.getAbsoluteFile(); // c:tempfilename.txt file = new File("dir"+File.separatorChar+"filename.txt"); file = file.getAbsoluteFile(); // c:tempdirfilename.txt file = new File(".."+File.separatorChar+"filename.txt"); file = file.getAbsoluteFile(); // c:temp..filename.txt // Note that filename.txt does not need to exist