/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License,
* Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied.
* See the License for the specific language governing permissions
* and limitations under the License.
*/
package org.apache.clerezza.rdf.web.core;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.security.AccessController;
import java.util.concurrent.locks.Lock;
import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.core.UriInfo;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.Service;
import org.apache.clerezza.jaxrs.utils.RedirectUtil;
import org.apache.clerezza.jaxrs.utils.form.FormFile;
import org.apache.clerezza.jaxrs.utils.form.MultiPartBody;
import org.apache.clerezza.rdf.core.Graph;
import org.apache.clerezza.rdf.core.MGraph;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.clerezza.rdf.core.Triple;
import org.apache.clerezza.rdf.core.TripleCollection;
import org.apache.clerezza.rdf.core.UriRef;
import org.apache.clerezza.rdf.core.access.LockableMGraph;
import org.apache.clerezza.rdf.core.access.NoSuchEntityException;
import org.apache.clerezza.rdf.core.access.TcManager;
import org.apache.clerezza.rdf.core.serializedform.Parser;
import org.apache.clerezza.web.fileserver.util.MediaTypeGuesser;
/**
* Provides methods to GET, PUT, and POST an SCB graph over the web.
* To be deployed in a JAX-RS runtime.
*
* @author hasan
*/
@Component
@Service(Object.class)
@Property(name="javax.ws.rs", boolValue=true)
@Path("/graph")
public class WebAccess {
@Reference
TcManager tcManager;
@Reference
private Parser parser;
final Logger logger = LoggerFactory.getLogger(WebAccess.class);
/**
* Gets the TripleCollection with specified name
*
* @param name
* @return
*/
@GET
public TripleCollection getTriples(@QueryParam("name") UriRef name) {
AccessController.checkPermission(new WebAccessPermission());
if (name == null) {
Response r = Response.status(Response.Status.BAD_REQUEST)
.entity("must specify a graph name")
.type(MediaType.TEXT_PLAIN_TYPE).build();
throw new WebApplicationException(r);
}
TripleCollection result = tcManager.getTriples(name);
logger.debug("Got graph of size {} ", result.size());
int i = 1;
if (logger.isDebugEnabled()) {
for (Triple triple : result) {
logger.debug("({}) with triples {}", i++, triple.toString());
}
logger.debug("returning");
}
return result;
}
/**
* Puts the triples replacing the triples of the existing MGraph with the
* specified name. If the graph doesn't exist creates a new <code>MGraph</code>
* with the specified name and puts the triples
*
*
* @param name
* @param triples
*/
@PUT
public void putTriples(@QueryParam("name") UriRef name, TripleCollection triples) {
AccessController.checkPermission(new WebAccessPermission());
LockableMGraph mGraph;
try {
mGraph = tcManager.getMGraph(name);
} catch (NoSuchEntityException e) {
mGraph = tcManager.createMGraph(name);
}
Lock writeLock = mGraph.getLock().writeLock();
writeLock.lock();
try {
mGraph.clear();
mGraph.addAll(triples);
} finally {
writeLock.unlock();
}
}
/**
* Posts triples to be placed into an {@link MGraph} of the specified name.
* If an {@link MGraph} with this name doesn't already exist, a new one
* is created and filled with the triples posted.
* @param form
* a multipart/form-data consisting of:
* - a {@link FormFile} labeled "graph" containing the triples and
* the mime-type.
* - a text field labeled "name" specifying the name of the MGraph.
* - an optional text field labeled "mode" specifying the mode.
* If the mode is "replace", existing triples of the MGraph will be
* deleted before new triples are added. If the mode is not
* specified or is "append", posted triples are added to the MGraph.
* - an optional text field labeled "redirection" specifying an URI
* which the client should be redirected to in case of success.
* @return
* {@link Response}. A response with status code BAD REQUEST (400) is
* returned if the required data are missing. If the request can be
* satisfied, one of the following responses is returned:
* - SEE OTHER (303), if redirection is specified.
* - CREATED (201), if redirection is not specified and a new
* {@link MGraph} is created.
* - NO CONTENT (204), if redirection is not specified and no new
* {@link MGraph} is created.
*/
@POST
@Consumes("multipart/form-data")
public Response postTriples(MultiPartBody form, @Context UriInfo uriInfo) {
AccessController.checkPermission(new WebAccessPermission());
FormFile[] formFiles = form.getFormFileParameterValues("graph");
if (formFiles.length == 0) {
responseWithBadRequest("form file parameter 'graph' is missing");
}
FormFile formFile = formFiles[0];
byte[] graph = formFile.getContent();
if (graph == null || (graph.length == 0)) {
responseWithBadRequest("no triples uploaded");
}
MediaType mediaType = formFile.getMediaType();
if (mediaType == null) {
responseWithBadRequest("mime-type not specified");
}
if (mediaType.equals(MediaType.APPLICATION_OCTET_STREAM_TYPE)) {
MediaType guessedType = MediaTypeGuesser.getInstance().guessTypeForName(formFile.getFileName());
if (guessedType != null) {
mediaType = guessedType;
}
}
String graphName = getFirstTextParameterValue(form, "name", true);
if (graphName == null) {
responseWithBadRequest("graph name not specified");
}
String mode = getFirstTextParameterValue(form, "mode", false);
if (mode != null) {
if (!(mode.equals("replace") || mode.equals("append"))) {
responseWithBadRequest("unknown mode");
}
} else {
mode = "append";
}
InputStream is = new ByteArrayInputStream(graph);
Graph parsedGraph = parser.parse(is, mediaType.toString());
UriRef graphUri = new UriRef(graphName);
LockableMGraph mGraph;
boolean newGraph = false;
try {
mGraph = tcManager.getMGraph(graphUri);
} catch (NoSuchEntityException e) {
mGraph = tcManager.createMGraph(graphUri);
newGraph = true;
}
Lock writeLock = mGraph.getLock().writeLock();
writeLock.lock();
try {
if (!newGraph && mode.equals("replace")) {
mGraph.clear();
}
mGraph.addAll(parsedGraph);
} finally {
writeLock.unlock();
}
String redirection = getFirstTextParameterValue(form, "redirection", false);
if (redirection == null) {
if (newGraph) {
return Response.status(Status.CREATED).build();
} else {
return Response.status(Status.NO_CONTENT).build();
}
}
return RedirectUtil.createSeeOtherResponse(redirection, uriInfo);
}
@GET
@Path("upload-form")
@Produces("application/xhtml+xml")
public InputStream getUploadForm() {
AccessController.checkPermission(new WebAccessPermission());
return getClass().getResourceAsStream("upload-form.xhtml");
}
private void responseWithBadRequest(String message) {
logger.warn(message);
throw new WebApplicationException(Response.status(Status.BAD_REQUEST)
.entity(message).build());
}
private String getFirstTextParameterValue(MultiPartBody form,
String parameterName, boolean mandatory) {
String[] paramValues = form.getTextParameterValues(parameterName);
if (paramValues.length == 0) {
if (mandatory) {
responseWithBadRequest("text parameter '" + parameterName +
"' is missing");
}
return null;
}
return paramValues[0];
}
}