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