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.ws.rs.Produces; 040import javax.ws.rs.core.MediaType; 041import javax.ws.rs.core.MultivaluedMap; 042import javax.ws.rs.ext.MessageBodyWriter; 043import javax.ws.rs.ext.Provider; 044 045import org.openrdf.rio.RDFFormat; 046import org.openrdf.rio.RDFWriterRegistry; 047import org.openrdf.rio.ntriples.NTriplesWriterFactory; 048import org.slf4j.Logger; 049 050/** 051 * Provides serialization for streaming RDF results. 052 * 053 * @author ajs6f 054 * @since Nov 19, 2013 055 */ 056@Provider 057@Produces({TURTLE, N3, N3_ALT2, RDF_XML, NTRIPLES, APPLICATION_XML, TEXT_PLAIN, TURTLE_X, JSON_LD}) 058public class RdfStreamProvider implements MessageBodyWriter<RdfNamespacedStream> { 059 060 private static final Logger LOGGER = getLogger(RdfStreamProvider.class); 061 062 @Override 063 public boolean isWriteable(final Class<?> type, final Type genericType, 064 final Annotation[] annotations, final MediaType mediaType) { 065 LOGGER.debug( 066 "Checking to see if we can serialize type: {} to mimeType: {}", 067 type.getName(), mediaType.toString()); 068 if (!RdfNamespacedStream.class.isAssignableFrom(type)) { 069 return false; 070 } 071 if (mediaType.equals(TEXT_HTML_TYPE) 072 || mediaType.equals(APPLICATION_XHTML_XML_TYPE) 073 || (mediaType.getType().equals("application") && mediaType 074 .getSubtype().equals("html"))) { 075 LOGGER.debug("Was asked for an HTML mimeType, returning false."); 076 return false; 077 } 078 LOGGER.debug("Assuming that this is an attempt to retrieve RDF, returning true."); 079 return true; 080 } 081 082 @Override 083 public long getSize(final RdfNamespacedStream t, final Class<?> type, 084 final Type genericType, final Annotation[] annotations, 085 final MediaType mediaType) { 086 // We do not know how long the stream is 087 return -1; 088 } 089 090 @Override 091 public void writeTo(final RdfNamespacedStream nsStream, final Class<?> type, 092 final Type genericType, final Annotation[] annotations, 093 final MediaType mediaType, 094 final MultivaluedMap<String, Object> httpHeaders, 095 final OutputStream entityStream) { 096 097 LOGGER.debug("Serializing an RdfStream to mimeType: {}", mediaType); 098 final RdfStreamStreamingOutput streamOutput = new RdfStreamStreamingOutput(nsStream.stream, 099 nsStream.namespaces, mediaType); 100 streamOutput.write(entityStream); 101 } 102 103 /** 104 * Add the correct mimeType for n-triples. 105 */ 106 @PostConstruct 107 public void registerMimeTypes() { 108 RDFWriterRegistry.getInstance().add(new NTriplesWithCorrectMimeType()); 109 } 110 111 /** 112 * OpenRDF uses the wrong mimeType for n-triples, so we offer the correct 113 * one as well. 114 * 115 * @author ajs6f 116 * @since Nov 20, 2013 117 */ 118 public static class NTriplesWithCorrectMimeType extends 119 NTriplesWriterFactory { 120 121 private static final RDFFormat NTRIPLESWITHCORRECTMIMETYPE = 122 new RDFFormat("N-Triples-with-correct-mimeType", 123 NTRIPLES, Charset.forName("US-ASCII"), "nt", 124 NO_NAMESPACES, NO_CONTEXTS); 125 126 @Override 127 public RDFFormat getRDFFormat() { 128 return NTRIPLESWITHCORRECTMIMETYPE; 129 } 130 } 131 132}