/*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* The Original Code is the Kowari Metadata Store.
*
* The Initial Developer of the Original Code is Plugged In Software Pty
* Ltd (http://www.pisoftware.com, mailto:info@pisoftware.com). Portions
* created by Plugged In Software Pty Ltd are Copyright (C) 2001,2002
* Plugged In Software Pty Ltd. All Rights Reserved.
*
* Contributor(s): N/A.
*
* [NOTE: The text of this Exhibit A may differ slightly from the text
* of the notices in the Source Code files of the Original Code. You
* should use the text of this Exhibit A rather than the text found in the
* Original Code Source Code for Your Modifications.]
*
*/
package org.mulgara.client.jrdf.util;
// Java 2 standard packages
import java.util.*;
// Log4J
import org.apache.log4j.Logger;
// JRDF
import org.mulgara.client.jrdf.*;
import org.jrdf.graph.*;
/**
* A VirtualClosableIteratorProxy implementation that uses an array of Triples.
* This might have been a general implementation but was specifically created for Triples.
*
* @created 2004-07-29
*
* @author <a href="mailto:robert.turner@tucanatech.com">Robert Turner</a>
*
* @version $Revision: 1.8 $
*
* @modified $Date: 2005/01/05 04:57:37 $
*
* @maintenanceAuthor $Author: newmana $
*
* @company <A href="mailto:info@PIsoftware.com">Plugged In Software</A>
*
* @copyright ©2001 <a href="http://www.pisoftware.com/">Plugged In
* Software Pty Ltd</a>
*
* @licence <a href="{@docRoot}/../../LICENCE">Mozilla Public License v1.1</a>
*/
public class ClosableArrayIteratorProxy
implements VirtualClosableIteratorProxy<Triple> {
/**
* Logger. This is named after the class.
*/
@SuppressWarnings("unused")
private final static Logger log = Logger.getLogger(
ClosableArrayIteratorProxy.class.
getName());
/** Data Source used by the iterator */
private List<Triple> data = null;
/** does all the work */
private Iterator<Triple> iterator = null;
/** Indicates the Iterator has been closed */
private boolean closed = false;
/**
* Default Constructor
*
*/
public ClosableArrayIteratorProxy(Triple [] dataSource) {
super();
//cannot proceed without valid data
if (dataSource == null) {
throw new IllegalArgumentException("Triple [] cannot be null.");
}
//copy data to List
this.data = new ArrayList<Triple>();
final int length = dataSource.length;
for (int i = 0; i < length; i++) {
this.data.add(dataSource[i]);
}
//get the List iterator
this.iterator = this.data.iterator();
}
/**
* Closes the iterator by freeing any resources that it current holds. This
* must be done as soon as possible. Once an iterator is closed none of the
* operations on a iterator will operate i.e. they will throw an exception.
*/
public boolean close() {
//empty the List
this.data.clear();
this.data = null;
this.closed = true;
//success...
return true;
}
/**
* Returns <tt>true</tt> if the iteration has more elements. (In other
* words, returns <tt>true</tt> if <tt>next</tt> would return an element
* rather than throwing an exception.)
*
* @return <tt>true</tt> if the iterator has more elements.
*/
public boolean hasNext() {
//ensure the iterator is not closed
if (this.closed) {
throw new IllegalStateException("ClosableIterator has been closed.");
}
return this.iterator.hasNext();
}
/**
* Returns the next Triple in the iteration.
*
* @return the next element in the iteration.
* @exception NoSuchElementException iteration has no more elements.
*/
public Triple next() {
//ensure the iterator is not closed
if (this.closed) {
throw new IllegalStateException("ClosableIterator has been closed.");
}
return this.iterator.next();
}
/**
* Let the iterator do it.
*
* @exception UnsupportedOperationException if the <tt>remove</tt>
* operation is not supported by this Iterator.
*/
public void remove() {
//ensure the iterator is not closed
if (this.closed) {
throw new IllegalStateException("ClosableIterator has been closed.");
}
this.iterator.remove();
}
}