/*
* $Header$
* $Revision: 982 $
* $Date: 2006-12-08 18:42:51 +1000 (Fri, 08 Dec 2006) $
*
* ====================================================================
*
* 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.query.client;
import org.jrdf.query.answer.Answer;
import static org.jrdf.util.param.ParameterUtil.checkNotNull;
import org.restlet.Client;
import static org.restlet.data.Method.GET;
import org.restlet.data.Reference;
import org.restlet.data.Request;
import org.restlet.data.Response;
import org.restlet.data.Status;
import org.restlet.resource.Representation;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;
public final class QueryClientImpl implements QueryClient {
private final URI endPointUri;
private Client client;
private final SparqlAnswerHandler answerHandler;
private Request request;
public QueryClientImpl(final URI newEndPointUri, final SparqlAnswerHandler newAnswerHandler) {
checkNotNull(newEndPointUri, newAnswerHandler);
this.endPointUri = newEndPointUri;
this.client = new Client(newEndPointUri.getScheme());
this.answerHandler = newAnswerHandler;
}
public void setQuery(final String sparqlQuery, final Map<String, String> queryExtensions) {
checkNotNull(sparqlQuery, queryExtensions);
final HashMap<String, String> map = new HashMap<String, String>(queryExtensions);
map.put("query", sparqlQuery);
request = new Request(GET, createReferenceFromQuery(map));
answerHandler.setAcceptedMediaTypes(request);
}
public Answer executeQuery() {
if (request == null) {
throw new IllegalStateException("No query to execute, call setQuery first");
}
return answerHandler.getAnswer(getRepresentation());
}
public Answer executeQuery(final String queryString, final Map<String, String> ext) {
checkNotNull(queryString, ext);
setQuery(queryString, ext);
return executeQuery();
}
public String toString() {
return request.getClientInfo().getAddress();
}
private Reference createReferenceFromQuery(final Map<String, String> queryParameters) {
validateEndPointUri();
final Reference ref = new Reference(endPointUri.getScheme(), endPointUri.getHost(), endPointUri.getPort(),
endPointUri.getPath(), null, null);
for (final Map.Entry<String, String> entry : queryParameters.entrySet()) {
ref.addQueryParameter(entry.getKey(), entry.getValue());
}
return ref;
}
private Representation getRepresentation() {
checkNotNull(client, request);
answerHandler.setAcceptedMediaTypes(request);
final Response response = client.handle(request);
final Status status = response.getStatus();
if (status.isSuccess()) {
return response.getEntity();
} else {
return handleFail(status);
}
}
private void validateEndPointUri() {
if (!endPointUri.isAbsolute()) {
throw new IllegalArgumentException("The SPARQL end point must have a scheme. Given URI: " + endPointUri);
}
}
private Representation handleFail(final Status status) {
final Throwable throwable = status.getThrowable();
if (throwable != null) {
throw new RuntimeException(throwable);
} else {
throw new RuntimeException(status.getDescription() + " (" + status.getCode() + ") from: " +
request.getResourceRef());
}
}
}