FileLock in XP environment

[Dennis Noren]

I've searched for how Win-XP handles shared locks and exclusive locks under nio, but have been unable to find anything yet. I have one program that reads a file, and does a shared lock of part of the file, then waits. A second program attempts to access a different portion of the file (no overlap) for writing. I get the run-time IOException:
"The process cannot access the file because another process has locked a portion of the file". This happens whether I use shared lock or exclusive lock.

Does someone know what XP allows in this situation, or whether I may be doing something that won't work regardless of the OS environment?

Thanks.

Code snippet from first program:

// Get shared lock on the file         
      FileLock fLock = fChan.lock(1,10,true);
      System.out.println();
      System.out.println(fLock.toString());
         
//Read bytes from the buffer.
      System.out.println();
      for(int i=0; i < fSize; i++)
      System.out.print((char)mBuf.get());
         
      System.out.println();
      try { 
 
         System.out.println("Waiting for comments on file");
         System.in.read(new byte[10]);
         
      } 
      catch (IOException exc) { 
         System.out.println(exc); 
         System.exit(1); 
      } 

Code snippet from second program:

//   Get lock on file for writing
       FileLock fLock = fChan.lock(21,30,true);
       System.out.println(fLock.toString());        

(the IOException occurs on the FileLock statement)