/*
* $Header$
* $Revision: 3169 $
* $Date: 2009-11-01 18:40:24 +1000 (Sun, 01 Nov 2009) $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2003-2009 The JRDF Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* the JRDF Project (http://jrdf.sf.net/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The JRDF Project" and "JRDF" must not be used to endorse
* or promote products derived from this software without prior written
* permission. For written permission, please contact
* newmana@users.sourceforge.net.
*
* 5. Products derived from this software may not be called "JRDF"
* nor may "JRDF" appear in their names without prior written
* permission of the JRDF Project.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the JRDF Project. For more
* information on JRDF, please see <http://jrdf.sourceforge.net/>.
*
*/
package org.jrdf.graph.local;
// JRDF objects
import org.jrdf.graph.AbstractBlankNode;
import org.jrdf.graph.BlankNode;
import org.jrdf.graph.global.GlobalizedBlankNode;
import static org.jrdf.util.EqualsUtil.isNull;
import static org.jrdf.util.EqualsUtil.sameReference;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* RDF blank node. Note that blank nodes are deliberately devoid of external indentifying attributes.
* <p/>
* Blank nodes, can either be subjects or objects.
*
* @author <a href="mailto:pgearon@users.sourceforge.net">Paul Gearon</a>
* @version $Revision: 3169 $
*/
public class BlankNodeImpl extends AbstractBlankNode implements GlobalizedBlankNode {
private static final int PRIME = 31;
private static final Pattern PATTERN = Pattern.compile("(.+)\\#(.+)");
/**
* Allow newer compiled version of the stub to operate when changes
* have not occurred with the class.
* NOTE : update this serialVersionUID when a method or a public member is
* deleted.
*/
private static final long serialVersionUID = 1573129076314000518L;
/**
* The internal identifier for this node.
*/
private Long id;
/**
* Globally Unique Identifier.
*/
private String uid;
/**
* The constructor for this node. Package scope so that only NodeFactory and
* static methods can call it.
*
* @param newUid String Globally Unique Identifier for external communication.
* @param newId The id to be used for this node.
*/
public BlankNodeImpl(String newUid, Long newId) {
id = newId;
uid = newUid;
}
/**
* Retrieves an internal identifier for this node.
*
* @return A numeric identifier for thisa node.
*/
public Long getId() {
return id;
}
/**
* Retrieves a Globally Unique Identifier for this node.
*
* @return A global String identifier for this node.
*/
public String getUID() {
return uid;
}
/**
* Returns a hash-code value for this BlankNode. While the implementation
* is not defined, if there is a blank node identifier then it should be
* the hash code generated from this. Hash code generation should follow
* the normal contract.
*
* @return a hash-code value for this blank node.
*/
@Override
public int hashCode() {
int hash = PRIME + id.hashCode();
return hash * PRIME + uid.hashCode();
}
/**
* While the internal structure of a BlankNode is not defined equality between
* two nodes should be able to be determined.
*
* @param obj the reference object with which to compare.
* @return true if this object is the same as the obj argument; false otherwise.
*/
@Override
public boolean equals(Object obj) {
if (isNull(obj)) {
return false;
}
if (sameReference(this, obj)) {
return true;
}
try {
GlobalizedBlankNode tmpNode = (GlobalizedBlankNode) obj;
return id.equals(tmpNode.getId()) && uid.equals(tmpNode.getUID());
} catch (ClassCastException cce) {
return false;
}
}
/**
* Returns the String value of this BlankNode as:
* uid#id (eg. 29fbf7ba364f1425dda058737d764603#69)
*
* @return String
*/
public String toString() {
return uid + "#" + id;
}
/**
* Parses a String in the format of:
* uid#id (eg. 29fbf7ba364f1425dda058737d764603#69) and creates a new BlankNodeImpl from it.
* <p/>
* Should only be applied to a value previously returned by toString()
*
* @param nodeString String previously returned by toString()
* @return BlankNodeImpl
* @throws IllegalArgumentException
*/
public static BlankNode valueOf(String nodeString) throws IllegalArgumentException {
Matcher matcher = PATTERN.matcher(nodeString);
if (matcher.matches() && matcher.groupCount() == 2) {
return new BlankNodeImpl(matcher.group(1), Long.valueOf(matcher.group(2)));
}
throw new IllegalArgumentException("String: " + nodeString + " is not of the format: uid#id");
}
}