/**
* tokenizes a given JCas object's document text using the treetagger program and adds the
* recognized tokens to the JCas object.
*
* @param jcas JCas object supplied by the pipeline
*/
private void tokenize(JCas jcas) {
// read tokenized text to add tokens to the jcas
Logger.printDetail(component, "TreeTagger (tokenization) with: " + ttprops.abbFileName);
EnumSet<Flag> flags = Flag.getSet(ttprops.languageSwitch);
TreeTaggerTokenizer ttt;
ttprops.abbFileName = "english-abbreviations";
if (ttprops.abbFileName != null) {
ttt =
new TreeTaggerTokenizer(
ttprops.rootPath
+ ttprops.fileSeparator
+ "lib"
+ ttprops.fileSeparator
+ ttprops.abbFileName,
flags);
} else {
ttt = new TreeTaggerTokenizer(null, flags);
}
String docText = jcas.getDocumentText().replaceAll("\n\n", "\nEMPTYLINE\n");
List<String> tokenized = ttt.tokenize(docText);
int tokenOffset = 0;
// loop through all the lines in the treetagger output
for (String s : tokenized) {
// charset missmatch fallback: signal (invalid) s
if ((!(s.equals("EMPTYLINE"))) && (jcas.getDocumentText().indexOf(s, tokenOffset) < 0))
throw new RuntimeException(
"Opps! Could not find token "
+ s
+ " in JCas after tokenizing with TreeTagger."
+ " Hmm, there may exist a charset missmatch!"
+ " Default encoding is "
+ Charset.defaultCharset().name()
+ " and should always be UTF-8 (use -Dfile.encoding=UTF-8)."
+ " If input document is not UTF-8 use -e option to set it according to the input, additionally.");
// create tokens and add them to the jcas's indexes.
Token newToken = new Token(jcas);
if (s.equals("EMPTYLINE")) {
newToken.setBegin(tokenOffset);
newToken.setEnd(tokenOffset);
newToken.setPos("EMPTYLINE");
if (annotate_partofspeech) {
newToken.addToIndexes();
}
} else {
newToken.setBegin(jcas.getDocumentText().indexOf(s, tokenOffset));
newToken.setEnd(newToken.getBegin() + s.length());
newToken.addToIndexes();
tokenOffset = newToken.getEnd();
}
}
}
/**
* based on tokens from the jcas object, adds part of speech (POS) and sentence tags to the jcas
* object using the treetagger program.
*
* @param jcas JCas object supplied by the pipeline
*/
private void doTreeTag(JCas jcas) {
File tmpDocument = null;
BufferedWriter tmpFileWriter;
ArrayList<Token> tokens = new ArrayList<Token>();
try {
// create a temporary file and write our pre-existing tokens to it.
tmpDocument = File.createTempFile("postokens", null);
tmpFileWriter =
new BufferedWriter(new OutputStreamWriter(new FileOutputStream(tmpDocument), "UTF-8"));
// iterate over existing tokens
FSIterator ai = jcas.getAnnotationIndex(Token.type).iterator();
while (ai.hasNext()) {
Token t = (Token) ai.next();
tokens.add(t);
if (!(t.getBegin() == t.getEnd())) {
tmpFileWriter.write(t.getCoveredText() + ttprops.newLineSeparator);
}
}
tmpFileWriter.close();
} catch (IOException e) {
Logger.printError(
"Something went wrong creating a temporary file for the treetagger to process.");
System.exit(-1);
}
// Possible End-of-Sentence Tags
HashSet<String> hsEndOfSentenceTag = new HashSet<String>();
hsEndOfSentenceTag.add("SENT"); // ENGLISH, FRENCH, GREEK,
hsEndOfSentenceTag.add("$."); // GERMAN, DUTCH
hsEndOfSentenceTag.add("FS"); // SPANISH
hsEndOfSentenceTag.add("_Z_Fst"); // ESTONIAN
hsEndOfSentenceTag.add("_Z_Int"); // ESTONIAN
hsEndOfSentenceTag.add("_Z_Exc"); // ESTONIAN
hsEndOfSentenceTag.add("ew"); // CHINESE
try {
Process p = ttprops.getTreeTaggingProcess(tmpDocument);
Logger.printDetail(component, "TreeTagger (pos tagging) with: " + ttprops.parFileName);
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream(), "UTF-8"));
Sentence sentence = null;
// iterate over all the output lines and tokens array (which have the same source and are
// hence symmetric)
int i = 0;
String s = null;
while ((s = in.readLine()) != null) {
// grab a token
Token token = tokens.get(i++);
// modified (Aug 29, 2011): Handle empty tokens (such as empty lines) in input file
while (token.getCoveredText().equals("")) {
// if part of the configuration, also add sentences to the jcas document
if ((annotate_sentences)
&& (token.getPos() != null && token.getPos().equals("EMPTYLINE"))) {
// Establish sentence structure
if (sentence == null) {
sentence = new Sentence(jcas);
sentence.setBegin(token.getBegin());
}
// Finish current sentence if end-of-sentence pos was found or document ended
sentence.setEnd(token.getEnd());
if (sentence.getBegin() < sentence.getEnd()) {
sentence.addToIndexes();
}
// Make sure current sentence is not active anymore so that a new one might be created
sentence = null;
// sentence = new Sentence(jcas);
}
token.removeFromIndexes();
token = tokens.get(i++);
}
// remove tokens, otherwise they are in the index twice
token.removeFromIndexes();
// set part of speech tag and add to indexes again
if (!(token.getCoveredText().equals(""))) {
token.setPos(s);
token.addToIndexes();
}
// if part of the configuration, also add sentences to the jcas document
if (annotate_sentences) {
// Establish sentence structure
if (sentence == null) {
sentence = new Sentence(jcas);
sentence.setBegin(token.getBegin());
}
// Finish current sentence if end-of-sentence pos was found or document ended
if (hsEndOfSentenceTag.contains(s) || i == tokens.size()) {
sentence.setEnd(token.getEnd());
sentence.addToIndexes();
// Make sure current sentence is not active anymore so that a new one might be created
sentence = null;
// sentence = new Sentence(jcas);
}
}
}
while (i < tokens.size()) {
if (!(sentence == null)) {
sentence.setEnd(tokens.get(tokens.size() - 1).getEnd());
sentence.addToIndexes();
}
Token token = tokens.get(i++);
if (token.getPos() != null && token.getPos().equals("EMPTYLINE")) {
token.removeFromIndexes();
}
}
in.close();
p.destroy();
} catch (Exception e) {
e.printStackTrace();
} finally {
// Delete temporary files
tmpDocument.delete();
}
}