1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18 package org.apache.commons.rdf.api;
19
20 import java.util.Arrays;
21 import java.util.Locale;
22 import java.util.Optional;
23
24 /**
25 * Enumeration of the RDF 1.1 serialization syntaxes.
26 * <p>
27 * This enumeration lists the W3C standardized RDF 1.1 syntaxes like
28 * {@link #TURTLE} and {@link #JSONLD}. Note the existence of other RDF syntaxes
29 * that are not included here, e.g.
30 * <a href="http://www.w3.org/TeamSubmission/n3/">N3</a> and
31 * <a href="https://en.wikipedia.org/wiki/TriX_%28syntax%29">TriX</a>.
32 *
33 * @see <a href="https://www.w3.org/TR/rdf11-primer/#section-graph-syntax">RDF
34 * 1.1 Primer</a>
35 * @see org.apache.commons.rdf.experimental.RDFParser
36 */
37 public enum RDFSyntax {
38
39 /**
40 * JSON-LD 1.0
41 *
42 * @see <a href=
43 * "https://www.w3.org/TR/json-ld/">https://www.w3.org/TR/json-ld/</a>
44 *
45 */
46 JSONLD("JSON-LD 1.0", "application/ld+json", ".jsonld", true),
47
48 /**
49 * RDF 1.1 Turtle
50 *
51 * @see <a href=
52 * "https://www.w3.org/TR/turtle/">https://www.w3.org/TR/turtle/</a>
53 *
54 */
55 TURTLE("RDF 1.1 Turtle", "text/turtle", ".ttl", false),
56
57 /**
58 * RDF 1.1 N-Quads
59 *
60 * @see <a href=
61 * "https://www.w3.org/TR/n-quads/">https://www.w3.org/TR/n-quads/</a>
62 */
63 NQUADS("RDF 1.1 N-Quads", "application/n-quads", ".nq", true),
64
65 /**
66 * RDF 1.1 N-Triples
67 *
68 * @see <a href=
69 * "https://www.w3.org/TR/n-triples/">https://www.w3.org/TR/n-triples/</a>
70 */
71 NTRIPLES("RDF 1.1 N-Triples", "application/n-triples", ".nt", false),
72
73 /**
74 * HTML+RDFa 1.1
75 *
76 * @see <a href=
77 * "https://www.w3.org/TR/html-rdfa/">https://www.w3.org/TR/html-rdfa/</a>
78 */
79 RDFA_HTML("HTML+RDFa 1.1", "text/html", ".html", false),
80
81 /**
82 * XHTML+RDFa 1.1
83 *
84 * @see <a href=
85 * "https://www.w3.org/TR/xhtml-rdfa/">https://www.w3.org/TR/xhtml-rdfa/</a>
86 */
87 RDFA_XHTML("XHTML+RDFa 1.1", "application/xhtml+xml", ".xhtml", false),
88
89 /**
90 * RDF 1.1 XML Syntax
91 *
92 * @see <a href=
93 * "https://www.w3.org/TR/rdf-syntax-grammar/">https://www.w3.org/TR/rdf-syntax-grammar/</a>
94 */
95 RDFXML("RDF 1.1 XML Syntax", "application/rdf+xml", ".rdf", false),
96
97 /**
98 * RDF 1.1 TriG
99 *
100 * @see <a href=
101 * "https://www.w3.org/TR/trig/">https://www.w3.org/TR/trig/</a>
102 */
103 TRIG("RDF 1.1 TriG", "application/trig", ".trig", true);
104
105 /**
106 * The <a href="https://tools.ietf.org/html/rfc2046">IANA media type</a> for
107 * the RDF syntax.
108 * <p>
109 * The media type can be used as part of <code>Content-Type</code> and
110 * <code>Accept</code> for <em>content negotiation</em> in the
111 * <a href="https://tools.ietf.org/html/rfc7231#section-3.1.1.1">HTTP
112 * protocol</a>.
113 */
114 public final String mediaType;
115
116 /**
117 * The <a href="https://tools.ietf.org/html/rfc2046">IANA-registered</a>
118 * file extension.
119 * <p>
120 * The file extension includes the leading period, e.g. <code>.jsonld</code>
121 */
122 public final String fileExtension;
123
124 /**
125 * Indicate if this RDF syntax supports
126 * <a href="https://www.w3.org/TR/rdf11-concepts/#section-dataset">RDF
127 * Datasets</a>.
128 */
129 public final boolean supportsDataset;
130
131 private final String name;
132
133 /**
134 * A human-readable name for the RDF syntax.
135 * <p>
136 * The name is equivalent to the the title of the corresponding W3C
137 * Specification.
138 */
139 @Override
140 public String toString() {
141 return name;
142 }
143
144 private RDFSyntax(final String name, final String mediaType, final String fileExtension, final boolean supportsDataset) {
145 this.name = name;
146 this.mediaType = mediaType;
147 this.fileExtension = fileExtension;
148 this.supportsDataset = supportsDataset;
149 }
150
151 /**
152 * Return the RDFSyntax with the specified media type.
153 * <p>
154 * The <code>mediaType</code> is compared in lower case, therefore it might
155 * not be equal to the {@link RDFSyntax#mediaType} of the returned
156 * RDFSyntax.
157 * <p>
158 * For convenience matching of media types used in a
159 * <code>Content-Type</code> header, if the <code>mediaType</code> contains
160 * the characters <code>;</code>, <code>,</code> or white space, only the
161 * part of the string to the left of those characters are considered.
162 *
163 * @param mediaType
164 * The media type to match
165 * @return If {@link Optional#isPresent()}, the {@link RDFSyntax} which has
166 * a matching {@link RDFSyntax#mediaType}, otherwise
167 * {@link Optional#empty()} indicating that no matching syntax was
168 * found.
169 */
170 public static Optional<RDFSyntax> byMediaType(final String mediaType) {
171 final String type = mediaType.toLowerCase(Locale.ENGLISH).split("\\s*[;,]", 2)[0];
172 return Arrays.stream(RDFSyntax.values()).filter(t -> t.mediaType.equals(type)).findAny();
173 }
174
175 /**
176 * Return the RDFSyntax with the specified file extension.
177 * <p>
178 * The <code>fileExtension</code> is compared in lower case, therefore it
179 * might not be equal to the {@link RDFSyntax#fileExtension} of the returned
180 * RDFSyntax.
181 *
182 * @param fileExtension
183 * The fileExtension to match, starting with <code>.</code>
184 * @return If {@link Optional#isPresent()}, the {@link RDFSyntax} which has
185 * a matching {@link RDFSyntax#fileExtension}, otherwise
186 * {@link Optional#empty()} indicating that no matching file
187 * extension was found.
188 */
189 public static Optional<RDFSyntax> byFileExtension(final String fileExtension) {
190 final String ext = fileExtension.toLowerCase(Locale.ENGLISH);
191 return Arrays.stream(RDFSyntax.values()).filter(t -> t.fileExtension.equals(ext)).findAny();
192 }
193
194 }