org.odftoolkit.odfdom.dom.rdfa.BookmarkRDFMetadataExtractor Maven / Gradle / Ivy
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package org.odftoolkit.odfdom.dom.rdfa;
import org.apache.jena.rdf.model.Resource;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import javax.xml.stream.XMLEventFactory;
import javax.xml.stream.events.Attribute;
import javax.xml.stream.events.StartElement;
import org.apache.jena.rdf.model.Model;
import org.apache.jena.rdf.model.ModelFactory;
import org.apache.jena.rdf.model.Property;
import org.odftoolkit.odfdom.dom.DefaultElementVisitor;
import org.odftoolkit.odfdom.dom.OdfDocumentNamespace;
import org.odftoolkit.odfdom.dom.element.text.TextBookmarkEndElement;
import org.odftoolkit.odfdom.dom.element.text.TextBookmarkStartElement;
import org.odftoolkit.odfdom.pkg.OdfElement;
import org.odftoolkit.odfdom.pkg.OdfFileDom;
import org.odftoolkit.odfdom.pkg.rdfa.DOMAttributes;
import org.odftoolkit.odfdom.pkg.rdfa.JenaSink;
import org.w3c.dom.Node;
import org.xml.sax.Attributes;
/**
* This is a sub class of DefaultElementVisitor, which is used to
* extract metadata from {@odf.element text:bookmark-start} to
* {@odf.element text:bookmark-end} pair.
*/
public class BookmarkRDFMetadataExtractor extends DefaultElementVisitor {
protected static final char NewLineChar = '\n';
protected static final char TabChar = '\t';
private TextBookmarkStartElement bookmarkstart;
private boolean found;
protected final Map builderMap;
protected final Map stringMap;
private XMLEventFactory eventFactory = XMLEventFactory.newInstance();
private JenaSink sink;
/**
* This class is used to provide the string builder functions to extractor.
* It will automatically process the last NewLineChar.
*
* @since 0.3.5
*/
protected static class ExtractorStringBuilder {
private StringBuilder mBuilder;
private boolean lastAppendNewLine;
ExtractorStringBuilder() {
mBuilder = new StringBuilder();
lastAppendNewLine = false;
}
/**
* Append a string
*
* @param str
* - the string
*/
public void append(String str) {
mBuilder.append(str);
}
/**
* Append a character
*
* @param ch
* - the character
*/
public void append(char ch) {
mBuilder.append(ch);
}
/**
* Append a new line character at the end
*/
public void appendLine() {
mBuilder.append(NewLineChar);
lastAppendNewLine = true;
}
/**
* Return the string value.
*
* If the last character is a new line character and is appended with
* appendLine(), the last new line character will be removed.
*/
public String toString() {
if (lastAppendNewLine) {
mBuilder.deleteCharAt(mBuilder.length() - 1);
}
return mBuilder.toString();
}
}
/**
* Create a BookmarkRDFMetadataExtractor instance, which RDF metadata
* content of bookmarks can be extracted by
* getBookmarkRDFMetadata().
*
* @param element
* the ODF element whose text will be extracted.
* @return an instance of BookmarkRDFMetadataExtractor
*/
public static BookmarkRDFMetadataExtractor newBookmarkTextExtractor() {
return new BookmarkRDFMetadataExtractor();
}
/**
* Return the RDF metadata of specified ODF element as a Jena Model.
*
* @return the text content as a string
*/
public Model getBookmarkRDFMetadata(OdfFileDom dom) {
this.bookmarkstart = null;
this.found = false;
this.sink = dom.getSink();
visit(dom.getRootElement());
return getModel();
}
public Model getBookmarkRDFMetadata(TextBookmarkStartElement bookmarkstart) {
this.bookmarkstart = bookmarkstart;
this.found = false;
this.sink = ((OdfFileDom) bookmarkstart.getOwnerDocument()).getSink();
visit(((OdfFileDom) bookmarkstart.getOwnerDocument()).getRootElement());
return getModel();
}
private Model getModel() {
Model m = ModelFactory.createDefaultModel();
for (Entry entry : stringMap
.entrySet()) {
String xhtmlAbout = entry.getKey().getXhtmlAboutAttribute();
String xhtmlProperty = entry.getKey().getXhtmlPropertyAttribute();
String xhtmlContent = entry.getKey().getXhtmlContentAttribute();
if (xhtmlAbout != null && xhtmlProperty != null) {
String qname = entry.getKey().getNodeName();
String namespaceURI = entry.getKey().getNamespaceURI();
String localname = entry.getKey().getLocalName();
String prefix = (qname.indexOf(':') == -1) ? "" : qname
.substring(0, qname.indexOf(':'));
StartElement e = eventFactory.createStartElement(prefix,
namespaceURI, localname,
fromAttributes(new DOMAttributes(entry.getKey()
.getAttributes())), null, sink.getContext());
xhtmlAbout = sink.getExtractor().expandSafeCURIE(e, xhtmlAbout,
sink.getContext());
xhtmlProperty = sink.getExtractor().expandCURIE(e,
xhtmlProperty, sink.getContext());
Resource s = m.createResource(xhtmlAbout);
Property p = m.createProperty(xhtmlProperty);
if (xhtmlContent != null) {
s.addLiteral(p, xhtmlContent);
} else {
s.addLiteral(p, entry.getValue());
}
}
}
return m;
}
private Iterator fromAttributes(Attributes attributes) {
List toReturn = new LinkedList();
for (int i = 0; i < attributes.getLength(); i++) {
String qname = attributes.getQName(i);
String prefix = qname.contains(":") ? qname.substring(0,
qname.indexOf(":")) : "";
Attribute attr = eventFactory.createAttribute(prefix,
attributes.getURI(i), attributes.getLocalName(i),
attributes.getValue(i));
if (!qname.equals("xmlns") && !qname.startsWith("xmlns:"))
toReturn.add(attr);
}
return toReturn.iterator();
}
/**
* Constructor with an ODF element as parameter
*
* @param element
* the ODF element whose text would be extracted.
*/
private BookmarkRDFMetadataExtractor() {
builderMap = new HashMap();
stringMap = new HashMap();
}
/**
* The end users needn't to care of this method, if you don't want to
* override the text content handling strategy of OdfElement.
*
* @see org.odftoolkit.odfdom.dom.DefaultElementVisitor#visit(org.odftoolkit.odfdom.pkg.OdfElement)
*/
@Override
public void visit(OdfElement element) {
if (bookmarkstart != null && found) {
return;
}
if (this.bookmarkstart == null) {
if (element instanceof TextBookmarkStartElement) {
builderMap.put((TextBookmarkStartElement) element,
new ExtractorStringBuilder());
}
} else {
if (element == bookmarkstart) {
builderMap.put((TextBookmarkStartElement) element,
new ExtractorStringBuilder());
}
}
appendElementText(element);
if (element.getNamespaceURI()
.equals(OdfDocumentNamespace.META.getUri())
|| element.getNamespaceURI().equals(
OdfDocumentNamespace.DC.getUri())) {
// textBuilderAppendLine();
}
}
/**
* Append the text content of this element to string buffer.
*
* @param ele
* the ODF element whose text will be appended.
*/
private void appendElementText(OdfElement ele) {
Node node = ele.getFirstChild();
while (node != null) {
if (node.getNodeType() == Node.TEXT_NODE) {
textBuilderAppend(node.getNodeValue());
} else if (node.getNodeType() == Node.ELEMENT_NODE) {
if (node instanceof TextBookmarkEndElement) {
TextBookmarkEndElement end = (TextBookmarkEndElement) node;
endBookmark(end);
}
OdfElement element = (OdfElement) node;
element.accept(this);
}
node = node.getNextSibling();
}
}
private void textBuilderAppendLine() {
for (Entry entry : builderMap
.entrySet()) {
entry.getValue().appendLine();
}
}
private void textBuilderAppend(char ch) {
for (Entry entry : builderMap
.entrySet()) {
entry.getValue().append(ch);
}
}
private void textBuilderAppend(String str) {
for (Entry entry : builderMap
.entrySet()) {
entry.getValue().append(str);
}
}
private void endBookmark(TextBookmarkEndElement end) {
TextBookmarkStartElement start = null;
for (Entry entry : builderMap
.entrySet()) {
if (entry.getKey().getTextNameAttribute()
.equals(end.getTextNameAttribute())) {
start = entry.getKey();
break;
}
}
if (start != null) {
stringMap.put(start, builderMap.get(start).toString());
builderMap.remove(start);
if (bookmarkstart != null) {
found = true;
}
}
}
}