Descriptor.java

/*
 * This file or a portion of this file is licensed under the terms of
 * the Globus Toolkit Public License, found in file GTPL, or at
 * http://www.globus.org/toolkit/download/license.html. This notice must
 * appear in redistributions of this file, with or without modification.
 *
 * Redistributions of this Software, with or without modification, must
 * reproduce the GTPL in: (1) the Software, or (2) the Documentation or
 * some other similar material which is provided with the Software (if
 * any).
 *
 * Copyright 1999-2004 University of Chicago and The University of
 * Southern California. All rights reserved.
 */
package edu.isi.pegasus.planner.invocation;

import java.util.*;
import java.io.Writer;
import java.io.IOException;

/**
 * This class is the container for a file descriptor object. A file
 * descriptor object contains just the descriptor number.
 *
 * @author Jens-S. Vöckler
 * @author Yong Zhao
 * @version $Revision$
 */
public class Descriptor extends File implements HasDescriptor
{
  /**
   * Descriptor of the file.
   */
  private int m_descriptor;

  /**
   * Default c'tor: Construct a hollow shell and allow further
   * information to be added later.
   */
  public Descriptor()
  {
    super();
    m_descriptor = -1;
  }

  /**
   * Constructs a file descriptor.
   * @param descriptor is a valid file descriptor number. 
   */
  public Descriptor( int descriptor )
  {
    super();
    m_descriptor = descriptor;
  }

  /**
   * Accessor
   *
   * @see #setDescriptor(int)
   */
  public int getDescriptor()
  { return this.m_descriptor; }

  /**
   * Accessor.
   *
   * @param descriptor
   * @see #getDescriptor()
   */
  public void setDescriptor( int descriptor )
  { this.m_descriptor = descriptor; }

  /**
   * Dump the state of the current element as XML output. This function
   * traverses all sibling classes as necessary, and converts the data
   * into pretty-printed XML output. The stream interface should be able
   * to handle large output efficiently.
   *
   * @param stream is a stream opened and ready for writing. This can also
   * be a string stream for efficient output.
   * @param indent is a <code>String</code> of spaces used for pretty
   * printing. The initial amount of spaces should be an empty string.
   * The parameter is used internally for the recursive traversal.
   * If a <code>null</code> value is specified, no indentation nor
   * linefeeds will be generated. 
   * @param namespace is the XML schema namespace prefix. If neither
   * empty nor null, each element will be prefixed with this prefix,
   * and the root element will map the XML namespace. 
   * @exception IOException if something fishy happens to the stream.
   */
  public void toXML( Writer stream, String indent, String namespace )
    throws IOException
  {
    String tag = ( namespace != null && namespace.length() > 0 ) ?
      namespace + ":descriptor" : "descriptor";

    // open tag
    if ( indent != null && indent.length() > 0 ) stream.write( indent );
    stream.write( '<' );
    stream.write( tag );
    writeAttribute( stream, " number=\"", Integer.toString(m_descriptor) );

    if ( m_hexbyte != null && m_hexbyte.length() > 0 ) {
      // yes, content
      stream.write( '>' );
      stream.write( m_hexbyte );
      stream.write( "</" );
      stream.write( tag );
      stream.write( '>' );
    } else {
      // no content
      stream.write( "/>" );
    }

    if ( indent != null ) 
      stream.write( System.getProperty( "line.separator", "\r\n" ) );
  }
}