Also see:

java.lang.System#out

Also see:

java.lang.System#err

 int decrementAndGetUseCount() 
{
        return useCount.decrementAndGet();
}

 int incrementAndGetUseCount() 
{
        return useCount.incrementAndGet();
}

 public native  void sync() throws SyncFailedException
Force all system buffers to synchronize with the underlying
device.  This method returns after all modified data and
attributes of this FileDescriptor have been written to the
relevant device(s).  In particular, if this FileDescriptor
refers to a physical storage medium, such as a file in a file
system, sync will not return until all in-memory modified copies
of buffers associated with this FileDesecriptor have been
written to the physical medium.

sync is meant to be used by code that requires physical
storage (such as a file) to be in a known state  For
example, a class that provided a simple transaction facility
might use sync to ensure that all changes to a file caused
by a given transaction were recorded on a storage medium.

sync only affects buffers downstream of this FileDescriptor.  If
any in-memory buffering is being done by the application (for
example, by a BufferedOutputStream object), those buffers must
be flushed into the FileDescriptor (for example, by invoking
OutputStream.flush) before that data will be affected by sync.

 public boolean valid() 
{
        return ((handle != -1) || (fd != -1));
}

Tests if this file descriptor object is valid.