/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Mar 5, 2012
*/
package com.bigdata.rdf.sail.webapp.client;
import java.util.HashMap;
import java.util.Map;
import org.openrdf.model.BNode;
import org.openrdf.model.Literal;
import org.openrdf.model.URI;
import org.openrdf.model.Value;
/**
* Utility class for externalizing SPARQL prefix declaration management.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class AST2SPARQLUtil {
/**
* The prefix declarations used within the SERVICE clause (from the original
* query).
*/
private final Map<String, String> prefixDecls;
/** Reverse map for {@link #prefixDecls}. */
private final Map<String, String> namespaces;
public AST2SPARQLUtil(final Map<String, String> prefixDecls) {
this.prefixDecls = prefixDecls;
if (prefixDecls != null) {
/*
* Build up a reverse map from namespace to prefix.
*/
namespaces = new HashMap<String, String>();
for (Map.Entry<String, String> e : prefixDecls.entrySet()) {
namespaces.put(e.getValue(), e.getKey());
}
} else {
namespaces = null;
}
}
/**
* Return an external form for the {@link Value} suitable for direct
* embedding into a SPARQL query.
*
* @param val
* The value.
*
* @return The external form.
*/
public String toExternal(final Value val) {
if (val instanceof URI) {
return toExternal((URI) val);
} else if (val instanceof Literal) {
return toExternal((Literal)val);
} else if (val instanceof BNode) {
return toExternal((BNode)val);
} else {
throw new AssertionError();
}
}
public String toExternal(final BNode bnd) {
final String id = bnd.stringValue();
// final boolean isLetter = Character.isLetter(id.charAt(0));
// return "_:" + (isLetter ? "" : "B") + id;
return "_:B" + id;
}
public String toExternal(final URI uri) {
if (prefixDecls != null) {
final String prefix = namespaces.get(uri.getNamespace());
if (prefix != null) {
return prefix + ":" + uri.getLocalName();
}
}
return "<" + uri.stringValue() + ">";
}
public String toExternal(final Literal lit) {
final String label = lit.getLabel();
final String languageCode = lit.getLanguage();
final URI datatypeURI = lit.getDatatype();
final String datatypeStr = datatypeURI == null ? null
: toExternal(datatypeURI);
final StringBuilder sb = new StringBuilder((label.length() + 2)
+ (languageCode != null ? (languageCode.length() + 1) : 0)
+ (datatypeURI != null ? datatypeStr.length() + 2 : 0));
sb.append('"');
sb.append(label);
sb.append('"');
if (languageCode != null) {
sb.append('@');
sb.append(languageCode);
}
if (datatypeURI != null) {
sb.append("^^");
sb.append(datatypeStr);
}
return sb.toString();
}
}