FedoraVersions.java

/**
 * Copyright 2013 DuraSpace, Inc.
 *
 * Licensed 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.fcrepo.http.api;

import static javax.ws.rs.core.Response.status;
import static javax.ws.rs.core.Response.Status.NOT_FOUND;
import static org.fcrepo.http.commons.domain.RDFMediaType.N3;
import static org.fcrepo.http.commons.domain.RDFMediaType.N3_ALT1;
import static org.fcrepo.http.commons.domain.RDFMediaType.N3_ALT2;
import static org.fcrepo.http.commons.domain.RDFMediaType.NTRIPLES;
import static org.fcrepo.http.commons.domain.RDFMediaType.POSSIBLE_RDF_VARIANTS;
import static org.fcrepo.http.commons.domain.RDFMediaType.RDF_JSON;
import static org.fcrepo.http.commons.domain.RDFMediaType.RDF_XML;
import static org.fcrepo.http.commons.domain.RDFMediaType.TURTLE;
import static org.slf4j.LoggerFactory.getLogger;

import java.io.IOException;
import java.util.List;

import javax.jcr.RepositoryException;
import javax.jcr.Session;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.PathSegment;
import javax.ws.rs.core.Request;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriInfo;
import javax.ws.rs.core.Variant;

import org.fcrepo.http.commons.AbstractResource;
import org.fcrepo.http.commons.api.rdf.HttpGraphSubjects;
import org.fcrepo.http.commons.responses.GraphStoreStreamingOutput;
import org.fcrepo.http.commons.session.InjectedSession;
import org.fcrepo.kernel.FedoraResource;
import org.slf4j.Logger;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

import com.hp.hpl.jena.query.Dataset;

/**
 * Endpoint for retrieving previous versions of nodes
 *
 * @todo note that the versioning mechanics are not fully wired up yet
 */
@Component
@Scope("prototype")
@Path("/{path: .*}/fcr:versions")
public class FedoraVersions extends AbstractResource {

    @InjectedSession
    protected Session session;

    private static final Logger LOGGER = getLogger(FedoraNodes.class);

    /**
     * Get the list of versions for the object
     *
     * @param pathList
     * @param request
     * @param uriInfo
     * @return
     * @throws RepositoryException
     */
    @GET
    @Produces({TURTLE, N3, N3_ALT1, N3_ALT2, RDF_XML, RDF_JSON, NTRIPLES})
    public Response getVersionList(@PathParam("path")
            final List<PathSegment> pathList,
            @Context
            final Request request,
            @Context
            final UriInfo uriInfo) throws RepositoryException {
        final String path = toPath(pathList);

        LOGGER.trace("getting versions list for {}", path);

        final Variant bestPossibleResponse =
                request.selectVariant(POSSIBLE_RDF_VARIANTS);

        try {
            final FedoraResource resource =
                    nodeService.getObject(session, path);

            return Response.ok(
                    new GraphStoreStreamingOutput(resource
                            .getVersionDataset(new HttpGraphSubjects(session,
                                                                        FedoraNodes.class,
                                                                        uriInfo)),
                            bestPossibleResponse.getMediaType())).build();

        } finally {
            session.logout();
        }

    }

    /**
     * Tag the current version of an object with the given label
     *
     * @param pathList
     * @param versionLabel
     * @return
     * @throws RepositoryException
     */
    @POST
    @Path("/{versionLabel}")
    public Response addVersionLabel(@PathParam("path")
            final List<PathSegment> pathList,
            @PathParam("versionLabel")
            final String versionLabel) throws RepositoryException {

        final String path = toPath(pathList);
        try {
            final FedoraResource resource =
                    nodeService.getObject(session, path);
            resource.addVersionLabel(versionLabel);

            return Response.noContent().build();
        } finally {
            session.logout();
        }
    }

    /**
     * Retrieve the tagged version of an object
     * @param pathList
     * @param versionLabel
     * @param uriInfo
     * @return
     * @throws RepositoryException
     * @throws IOException
     */
    @Path("/{versionLabel}")
    @GET
    @Produces({TURTLE, N3, N3_ALT1, N3_ALT2, RDF_XML, RDF_JSON, NTRIPLES})
    public Dataset getVersion(@PathParam("path")
            final List<PathSegment> pathList,
            @PathParam("versionLabel")
            final String versionLabel,
            @Context
            final UriInfo uriInfo) throws RepositoryException, IOException {
        final String path = toPath(pathList);
        LOGGER.trace("getting version profile for {} at version {}", path,
                versionLabel);

        try {
            final FedoraResource resource =
                    nodeService.getObject(session, path, versionLabel);

            if (resource == null) {
                throw new WebApplicationException(status(NOT_FOUND).build());
            } else {

                return resource.getPropertiesDataset(new HttpGraphSubjects(
                        session, FedoraNodes.class, uriInfo), 0, -1);
            }

        } finally {
            session.logout();
        }

    }
}