/*
* 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.demo.mp3.id3;
// Java 2 standard packages
// Logging
import org.apache.log4j.Logger;
// JRDF
import org.jrdf.graph.URIReference;
import org.jrdf.util.ClosableIterator;
// Local Packages
import org.jrdf.graph.Triple;
import java.net.URI;
import org.mulgara.demo.mp3.Mp3Context;
import org.mulgara.demo.mp3.Mp3File;
import org.mulgara.demo.mp3.Mp3Model;
import org.mulgara.demo.mp3.SchemaModel;
import org.mulgara.itql.*;
import org.mulgara.query.QueryException;
import org.mulgara.query.rdf.TripleImpl;
import org.mulgara.query.rdf.URIReferenceImpl;
import org.jrdf.graph.*;
import java.util.*;
/**
* Default Id3Tag base class.
*
* @created 2004-12-03
*
* @author <a href="mailto:robert.turner@tucanatech.com">Robert Turner</a>
*
* @version $Revision: 1.3 $
*
* @modified $Date: 2005/01/05 04:58:06 $
*
* @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 abstract class AbstractId3Tag implements Id3Tag {
/**
* Logger. This is named after the class.
*/
private final static Logger log = Logger.getLogger(AbstractId3Tag.class.
getName());
/** Used to perform queries */
private ItqlInterpreterBean bean = null;
/** Graph containing the Mp3 instance data */
private Mp3Model model = null;
/** Graph containing Schema information */
private SchemaModel schemaModel = null;
/** Mp3File that this Tag represents. */
private Mp3File mp3 = null;
/**
* Initializes the Id3Tag.
* @param context Mp3Context
*/
public void init(Mp3Context context) {
if (context == null) {
throw new IllegalArgumentException("Mp3Context is null.");
}
bean = context.getBean();
model = context.getMp3Model();
schemaModel = context.getSchemaModel();
//validate
if (bean == null) {
throw new IllegalArgumentException("Mp3Context returned a null " +
"ItqlInterpreterBean.");
}
if (model == null) {
throw new IllegalArgumentException("Mp3Context returned a null Mp3Model.");
}
if (schemaModel == null) {
throw new IllegalArgumentException("Mp3Context returned a null " +
"SchemaModel.");
}
}
/**
* Returns the Resource URI for the ID3 tag's version (eg. Id3Tag.ID3V1).
* @return URIReference never <code>null</code>
*/
public abstract URIReference getVersion();
/**
* Sets the Mp3 that the Id3Tag represents
* @param mp3 Mp3File
*/
public void setMp3File(Mp3File mp3) {
if (mp3 == null) {
throw new IllegalArgumentException("Mp3File is null.");
}
this.mp3 = mp3;
}
/**
* Returns the Mp3 that the Id3Tag represents
* @return Mp3File
*/
public Mp3File getMp3File() {
return mp3;
}
/**
* Returns all Id3 property-values for the Mp3 as an Iterator of Triples.
*
* @return ClosableIterator
* @throws QueryException
*/
public ClosableIterator getSchemaProperties() throws QueryException {
//the id3 version is the RDFS domain
return schemaModel.getDomainProperties(getVersion());
}
/**
* Returns all Id3 property-values for the Mp3 as an Iterator of Triples.
*
* @return ClosableIterator
* @throws QueryException
*/
public ClosableIterator getStatements() throws QueryException {
ClosableIterator schemaProperties = null;
try {
schemaProperties = getSchemaProperties();
String query = getStatementsQuery(mp3.getResource(), schemaProperties);
return model.query(query);
}
catch (Exception exception) {
throw new QueryException("Failed to getStatements.", exception);
}
finally {
if (schemaProperties != null) {
schemaProperties.close();
}
}
}
/**
* Returns a queryString in the following format:
*
* <p> <pre>
* select $s $p $o
* from <model.getResource()>
* where $s $p $o
* and $s <id3:uri> <mp3>
* and ($p <mulgara:is> <schemaProperty-1>
* or $p <mulgara:is> <schemaProperty-2>
* ...
* or $p <mulgara:is> <schemaProperty-n>) ;
* </pre> where <schemaProperty> is a property of the ID3Tags schema.
*
* @return String
* @param mp3 URIReference
* @param properties Iterator of Triples where the SubjectNode's represent the
* schemaProperties.
*/
private String getStatementsQuery(URIReference mp3, Iterator properties) {
//if there are no properties, there should be no statements.
if ((properties == null)
|| !(properties.hasNext())) {
return ";";
}
Node currentProperty = ((Triple) properties.next()).getPredicate();
StringBuffer query = new StringBuffer("select $s $p $o" + NEWLINE);
query.append("from <" + model.getResource().getURI() + ">" + NEWLINE);
query.append("where $s $p $o" + NEWLINE);
query.append("and $s" + ID3_URI + asString(mp3) + " " + NEWLINE);
query.append("and ( $p" + MULGARA_IS + asString((URIReference) currentProperty) +
" " + NEWLINE);
while (properties.hasNext()) {
currentProperty = ((Triple) properties.next()).getSubject();
query.append(" or $p" + MULGARA_IS + asString((URIReference) currentProperty) +
" " + NEWLINE);
}
//results must be ordered
query.append(") order by $s $p $o ; ");
return query.toString();
}
/**
* Determines if the object is a Literal or Resource and returns an iTQL
* representation.
*
* <p>Throws an Exception if the ObjectNode is a BlankNode
*
* @param node ObjectNode
* @return String
*/
protected String asString(Node node) {
if (node == null) {
throw new IllegalArgumentException("Node is null");
}
//determine type and convert to String
if (node instanceof URIReference) {
return " <" + ((URIReference) node).getURI() + ">";
}
else if (node instanceof Literal) {
return " '" + escape(((Literal) node).getLexicalForm()) + "'";
}
else {
//probably a BlankNode
throw new IllegalArgumentException("Unsupported Node type: " +
node.getClass().getName());
}
}
/**
* replace all quotes ', " with \', \"
*
* @param literal String
* @return String
*/
protected String escape(String literal) {
String escaped = literal;
if (literal != null) {
escaped = escaped.replaceAll("'", "\\\\'");
// escaped = escaped.replaceAll("\"", "\\\"");
}
return escaped;
}
}