001/** 002 * Copyright 2015 DuraSpace, Inc. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016package org.fcrepo.http.commons.responses; 017 018import static javax.ws.rs.core.MediaType.APPLICATION_XHTML_XML_TYPE; 019import static javax.ws.rs.core.MediaType.APPLICATION_XML; 020import static javax.ws.rs.core.MediaType.TEXT_HTML_TYPE; 021import static javax.ws.rs.core.MediaType.TEXT_PLAIN; 022import static org.fcrepo.http.commons.domain.RDFMediaType.JSON_LD; 023import static org.fcrepo.http.commons.domain.RDFMediaType.N3; 024import static org.fcrepo.http.commons.domain.RDFMediaType.N3_ALT2; 025import static org.fcrepo.http.commons.domain.RDFMediaType.NTRIPLES; 026import static org.fcrepo.http.commons.domain.RDFMediaType.RDF_XML; 027import static org.fcrepo.http.commons.domain.RDFMediaType.TURTLE; 028import static org.fcrepo.http.commons.domain.RDFMediaType.TURTLE_X; 029import static org.openrdf.rio.RDFFormat.NO_CONTEXTS; 030import static org.openrdf.rio.RDFFormat.NO_NAMESPACES; 031import static org.slf4j.LoggerFactory.getLogger; 032 033import java.io.OutputStream; 034import java.lang.annotation.Annotation; 035import java.lang.reflect.Type; 036import java.nio.charset.Charset; 037 038import javax.annotation.PostConstruct; 039import javax.jcr.RepositoryException; 040import javax.ws.rs.Produces; 041import javax.ws.rs.WebApplicationException; 042import javax.ws.rs.core.MediaType; 043import javax.ws.rs.core.MultivaluedMap; 044import javax.ws.rs.ext.MessageBodyWriter; 045import javax.ws.rs.ext.Provider; 046 047import org.fcrepo.kernel.api.utils.iterators.RdfStream; 048import org.fcrepo.kernel.modeshape.rdf.impl.NamespaceRdfContext; 049import org.openrdf.rio.RDFFormat; 050import org.openrdf.rio.RDFWriterRegistry; 051import org.openrdf.rio.ntriples.NTriplesWriterFactory; 052import org.slf4j.Logger; 053 054/** 055 * Provides serialization for streaming RDF results. 056 * 057 * @author ajs6f 058 * @since Nov 19, 2013 059 */ 060@Provider 061@Produces({TURTLE, N3, N3_ALT2, RDF_XML, NTRIPLES, APPLICATION_XML, TEXT_PLAIN, TURTLE_X, JSON_LD}) 062public class RdfStreamProvider implements MessageBodyWriter<RdfStream> { 063 064 private static final Logger LOGGER = getLogger(RdfStreamProvider.class); 065 066 @Override 067 public boolean isWriteable(final Class<?> type, final Type genericType, 068 final Annotation[] annotations, final MediaType mediaType) { 069 LOGGER.debug( 070 "Checking to see if we can serialize type: {} to mimeType: {}", 071 type.getName(), mediaType.toString()); 072 if (!RdfStream.class.isAssignableFrom(type)) { 073 return false; 074 } 075 if (mediaType.equals(TEXT_HTML_TYPE) 076 || mediaType.equals(APPLICATION_XHTML_XML_TYPE) 077 || (mediaType.getType().equals("application") && mediaType 078 .getSubtype().equals("html"))) { 079 LOGGER.debug("Was asked for an HTML mimeType, returning false."); 080 return false; 081 } 082 LOGGER.debug("Assuming that this is an attempt to retrieve RDF, returning true."); 083 return true; 084 } 085 086 @Override 087 public long getSize(final RdfStream t, final Class<?> type, 088 final Type genericType, final Annotation[] annotations, 089 final MediaType mediaType) { 090 // We do not know how long the stream is 091 return -1; 092 } 093 094 @Override 095 public void writeTo(final RdfStream rdfStream, final Class<?> type, 096 final Type genericType, final Annotation[] annotations, 097 final MediaType mediaType, 098 final MultivaluedMap<String, Object> httpHeaders, 099 final OutputStream entityStream) { 100 101 LOGGER.debug("Serializing an RdfStream to mimeType: {}", mediaType); 102 try { 103 if (rdfStream.namespaces().isEmpty()) { 104 final RdfStream namespaceRdfContext = new NamespaceRdfContext(rdfStream.session()); 105 rdfStream.namespaces(namespaceRdfContext.namespaces()); 106 } 107 108 final RdfStreamStreamingOutput streamOutput = new RdfStreamStreamingOutput(rdfStream, mediaType); 109 streamOutput.write(entityStream); 110 } catch (final RepositoryException e) { 111 throw new WebApplicationException(e); 112 } 113 114 115 } 116 117 /** 118 * Add the correct mimeType for n-triples. 119 */ 120 @PostConstruct 121 public void registerMimeTypes() { 122 RDFWriterRegistry.getInstance().add(new NTriplesWithCorrectMimeType()); 123 } 124 125 /** 126 * OpenRDF uses the wrong mimeType for n-triples, so we offer the correct 127 * one as well. 128 * 129 * @author ajs6f 130 * @since Nov 20, 2013 131 */ 132 public static class NTriplesWithCorrectMimeType extends 133 NTriplesWriterFactory { 134 135 private static final RDFFormat NTRIPLESWITHCORRECTMIMETYPE = 136 new RDFFormat("N-Triples-with-correct-mimeType", 137 NTRIPLES, Charset.forName("US-ASCII"), "nt", 138 NO_NAMESPACES, NO_CONTEXTS); 139 140 @Override 141 public RDFFormat getRDFFormat() { 142 return NTRIPLESWITHCORRECTMIMETYPE; 143 } 144 } 145 146}