This class is a platform-independent representation of a low-level handle to an open file or socket. The static in , out, and err variables are FileDescriptor objects that represent the standard input, output, and error streams, respectively. There is no public constructor method to create a FileDescriptor object. You can obtain one with the getFD( ) method of FileInputStream, FileOutputStream, or RandomAccessFile.

public final class FileDescriptor {
// Public Constructors
     public FileDescriptor( );  
// Public Constants
     public static final FileDescriptor err;  
     public static final FileDescriptor in;  
     public static final FileDescriptor out;  
// Public Instance Methods
1.1  public void sync( ) throws SyncFailedException;                  native
     public boolean valid( );  
}

Passed To

FileInputStream.FileInputStream( ), FileOutputStream.FileOutputStream( ), FileReader.FileReader( ), FileWriter.FileWriter( ), SecurityManager.{checkRead( ), checkWrite( )}

Returned By

FileInputStream.getFD( ), FileOutputStream.getFD( ), RandomAccessFile.getFD( ), java.net.DatagramSocketImpl.getFileDescriptor( ), java.net.SocketImpl.getFileDescriptor( )

Type Of

java.net.DatagramSocketImpl.fd, java.net.SocketImpl.fd