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18 package org.apache.any23.extractor.html;
19
20 import org.apache.any23.extractor.ExtractionContext;
21 import org.apache.any23.extractor.ExtractionException;
22 import org.apache.any23.extractor.ExtractionParameters;
23 import org.apache.any23.extractor.ExtractionResult;
24 import org.apache.any23.extractor.ExtractorDescription;
25 import org.apache.any23.rdf.Any23ValueFactoryWrapper;
26 import org.apache.any23.vocab.FOAF;
27 import org.apache.any23.vocab.XFN;
28 import org.apache.any23.extractor.Extractor.TagSoupDOMExtractor;
29 import org.eclipse.rdf4j.model.BNode;
30 import org.eclipse.rdf4j.model.IRI;
31 import org.eclipse.rdf4j.model.impl.SimpleValueFactory;
32 import org.eclipse.rdf4j.model.vocabulary.RDF;
33 import org.w3c.dom.Document;
34 import org.w3c.dom.Node;
35
36 import java.io.IOException;
37 import java.util.Locale;
38
39
40
41
42
43
44 public class XFNExtractor implements TagSoupDOMExtractor {
45
46 private static final FOAF vFOAF = FOAF.getInstance();
47 private static final XFN vXFN = XFN.getInstance();
48
49 private final static Any23ValueFactoryWrapper factoryWrapper = new Any23ValueFactoryWrapper(
50 SimpleValueFactory.getInstance());
51
52 private HTMLDocument document;
53 private ExtractionResult out;
54
55 @Override
56 public ExtractorDescription getDescription() {
57 return XFNExtractorFactory.getDescriptionInstance();
58 }
59
60 @Override
61 public void run(ExtractionParameters extractionParameters, ExtractionContext extractionContext, Document in,
62 ExtractionResult out) throws IOException, ExtractionException {
63 factoryWrapper.setIssueReport(out);
64 try {
65 document = new HTMLDocument(in);
66 this.out = out;
67
68 BNode subject = factoryWrapper.createBNode();
69 boolean foundAnyXFN = false;
70 final IRI documentIRI = extractionContext.getDocumentIRI();
71 for (Node link : document.findAll("//A[@rel][@href]")) {
72 foundAnyXFN |= extractLink(link, subject, documentIRI);
73 }
74 if (!foundAnyXFN)
75 return;
76 out.writeTriple(subject, RDF.TYPE, vFOAF.Person);
77 out.writeTriple(subject, vXFN.mePage, documentIRI);
78 } finally {
79 factoryWrapper.setIssueReport(null);
80 }
81 }
82
83 private boolean extractLink(Node firstLink, BNode subject, IRI documentIRI) throws ExtractionException {
84 Node hrefNodeItem = firstLink.getAttributes().getNamedItem("href");
85 Node relNodeItem = firstLink.getAttributes().getNamedItem("rel");
86 if (hrefNodeItem == null || relNodeItem == null) {
87 return false;
88 }
89 String href = hrefNodeItem.getNodeValue();
90 String rel = relNodeItem.getNodeValue();
91
92 String[] rels = rel.split("\\s+");
93 IRI link = document.resolveIRI(href);
94 if (containsRelMe(rels)) {
95 if (containsXFNRelExceptMe(rels)) {
96 return false;
97 }
98 out.writeTriple(subject, vXFN.mePage, link);
99 out.writeTriple(documentIRI, vXFN.getExtendedProperty("me"), link);
100 } else {
101 BNode person2 = factoryWrapper.createBNode();
102 boolean foundAnyXFNRel = false;
103 for (String aRel : rels) {
104 foundAnyXFNRel |= extractRel(aRel, subject, documentIRI, person2, link);
105 }
106 if (!foundAnyXFNRel) {
107 return false;
108 }
109 out.writeTriple(person2, RDF.TYPE, vFOAF.Person);
110 out.writeTriple(person2, vXFN.mePage, link);
111 }
112 return true;
113 }
114
115 private boolean containsRelMe(String[] rels) {
116 for (String rel : rels) {
117 if ("me".equals(rel.toLowerCase(Locale.ROOT))) {
118 return true;
119 }
120 }
121 return false;
122 }
123
124 private boolean containsXFNRelExceptMe(String[] rels) {
125 for (String rel : rels) {
126 if (!"me".equals(rel.toLowerCase(Locale.ROOT)) && vXFN.isXFNLocalName(rel)) {
127 return true;
128 }
129 }
130 return false;
131 }
132
133 private boolean extractRel(String rel, BNode person1, IRI uri1, BNode person2, IRI uri2) {
134 IRI peopleProp = vXFN.getPropertyByLocalName(rel);
135 IRI hyperlinkProp = vXFN.getExtendedProperty(rel);
136 if (peopleProp == null) {
137 return false;
138 }
139 out.writeTriple(person1, peopleProp, person2);
140 out.writeTriple(uri1, hyperlinkProp, uri2);
141 return true;
142 }
143
144 }