How to RELIABLY compare two File objects?

Question

Hi java community!
I have two File objects and I need to know whether they both point to the same file on the system. First, I tried using the equals() method of the File object, but later I found that this often returns false even when file being pointed to by both objects is the same file.
For example:
  public static void main(String[] args) throws Exception {
    File mFileA = new File("C:\\PROGRA~1\\MYPROG~1\\MYDATA~1.TXT");
    File mFileB = new File("C:\\Program Files\\My Program\\My Data File.txt");
    DataInputStream mInputA = new DataInputStream(new BufferedInputStream(new FileInputStream(mFileA)));
    DataInputStream mInputB = new DataInputStream(new BufferedInputStream(new FileInputStream(mFileB)));
    System.out.println("Contents of file A:");
    while (mInputA.available() > 0) {
      System.out.println(mInputA.readLine());
    System.out.println("\nContents of file B:");
    while (mInputB.available() > 0) {
      System.out.println(mInputB.readLine());
    System.out.println("\nAre file A and file B the same file?");
    System.out.println(mFileA.equals(mFileB) ? "Yes" : "No");
  }Running this gives the following output:
Contents of file A:
First line of the file.
Second line of the file.
Third and final line of the file.
Contents of file B:
First line of the file.
Second line of the file.
Third and final line of the file.
Are file A and file B the same file?
NoIt seems that the different representation of the paths (short 8.3 file names, vs. long file names) is confusing Java into believing that they are two separate files, even though the example above confirms that they are in fact the same file by showing the contents from input streams derived by the two File objects (which are, needless to say, identical).
So, does anyone know how to reliably determine whether two File objects point to the same file?
Cheers,
Martin

Answer 1

sabre150 wrote:
Bren_McGuire wrote:
Thanks guys.
I'd just found it too right after I made this post. :p95% of the time the promised Dukes never arrive so thanks for the Dukes.Ditto