Question

I want to do a very simple job: given a string containing pronouns, I want to resolve them.

for example, I want to turn the sentence “Mary has a little lamb. She is cute.” in “Mary has a little lamb. Mary is cute.”.

I have tried to use Stanford CoreNLP. However, I seem unable to get the parser to start. I have imported all the included jars in my project using Eclipse, and I have allocated 3GB to the JVM (-Xmx3g).

The error is very awkward:

Exception in thread “main” java.lang.NoSuchMethodError:
edu.stanford.nlp.parser.lexparser.LexicalizedParser.loadModel(Ljava/lang/String;[Ljava/lang/String;)Ledu/stanford/nlp/parser/lexparser/LexicalizedParser;

I don’t understand where that L comes from, I think it is the root of my problem… This is rather weird. I have tried to get inside the source files, but there is no wrong reference there.

Code:

import edu.stanford.nlp.semgraph.SemanticGraphCoreAnnotations.CollapsedCCProcessedDependenciesAnnotation;
import edu.stanford.nlp.dcoref.CorefCoreAnnotations.CorefChainAnnotation;
import edu.stanford.nlp.dcoref.CorefCoreAnnotations.CorefGraphAnnotation;
import edu.stanford.nlp.ling.CoreAnnotations.NamedEntityTagAnnotation;
import edu.stanford.nlp.ling.CoreAnnotations.PartOfSpeechAnnotation;
import edu.stanford.nlp.ling.CoreAnnotations.SentencesAnnotation;
import edu.stanford.nlp.ling.CoreAnnotations.TextAnnotation;
import edu.stanford.nlp.ling.CoreAnnotations.TokensAnnotation;
import edu.stanford.nlp.trees.TreeCoreAnnotations.TreeAnnotation;
import edu.stanford.nlp.ling.CoreLabel;
import edu.stanford.nlp.dcoref.CorefChain;
import edu.stanford.nlp.pipeline.*;
import edu.stanford.nlp.trees.Tree;
import edu.stanford.nlp.semgraph.SemanticGraph;
import edu.stanford.nlp.util.CoreMap;
import edu.stanford.nlp.util.IntTuple;
import edu.stanford.nlp.util.Pair;
import edu.stanford.nlp.util.Timing;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import java.util.Properties;

public class Coref {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) throws IOException, ClassNotFoundException {
    // creates a StanfordCoreNLP object, with POS tagging, lemmatization, NER, parsing, and coreference resolution 
    Properties props = new Properties();
    props.put("annotators", "tokenize, ssplit, pos, lemma, ner, parse, dcoref");
    StanfordCoreNLP pipeline = new StanfordCoreNLP(props);

    // read some text in the text variable
    String text = "Mary has a little lamb. She is very cute."; // Add your text here!

    // create an empty Annotation just with the given text
    Annotation document = new Annotation(text);

    // run all Annotators on this text
    pipeline.annotate(document);

    // these are all the sentences in this document
    // a CoreMap is essentially a Map that uses class objects as keys and has values with custom types
    List<CoreMap> sentences = document.get(SentencesAnnotation.class);

    for(CoreMap sentence: sentences) {
      // traversing the words in the current sentence
      // a CoreLabel is a CoreMap with additional token-specific methods
      for (CoreLabel token: sentence.get(TokensAnnotation.class)) {
        // this is the text of the token
        String word = token.get(TextAnnotation.class);
        // this is the POS tag of the token
        String pos = token.get(PartOfSpeechAnnotation.class);
        // this is the NER label of the token
        String ne = token.get(NamedEntityTagAnnotation.class);       
      }

      // this is the parse tree of the current sentence
      Tree tree = sentence.get(TreeAnnotation.class);
      System.out.println(tree);

      // this is the Stanford dependency graph of the current sentence
      SemanticGraph dependencies = sentence.get(CollapsedCCProcessedDependenciesAnnotation.class);
    }

    // This is the coreference link graph
    // Each chain stores a set of mentions that link to each other,
    // along with a method for getting the most representative mention
    // Both sentence and token offsets start at 1!
    Map<Integer, CorefChain> graph = 
      document.get(CorefChainAnnotation.class);
    System.out.println(graph);
  }
}

Full stack trace:

Adding annotator tokenize
Adding annotator ssplit
Adding annotator pos
Loading POS Model [edu/stanford/nlp/models/pos-tagger/english-left3words/english-left3words-distsim.tagger] … Loading default properties from trained tagger edu/stanford/nlp/models/pos-tagger/english-left3words/english-left3words-distsim.tagger
Reading POS tagger model from edu/stanford/nlp/models/pos-tagger/english-left3words/english-left3words-distsim.tagger … done [2.1 sec].
done [2.2 sec].
Adding annotator lemma
Adding annotator ner
Loading classifier from edu/stanford/nlp/models/ner/english.all.3class.distsim.crf.ser.gz … done [4.0 sec].
Loading classifier from edu/stanford/nlp/models/ner/english.muc.distsim.crf.ser.gz … done [3.0 sec].
Loading classifier from edu/stanford/nlp/models/ner/english.conll.distsim.crf.ser.gz … done [3.3 sec].
Adding annotator parse
Exception in thread “main” java.lang.NoSuchMethodError: edu.stanford.nlp.parser.lexparser.LexicalizedParser.loadModel(Ljava/lang/String;[Ljava/lang/String;)Ledu/stanford/nlp/parser/lexparser/LexicalizedParser;
at edu.stanford.nlp.pipeline.ParserAnnotator.loadModel(ParserAnnotator.java:115)
at edu.stanford.nlp.pipeline.ParserAnnotator.(ParserAnnotator.java:64)
at edu.stanford.nlp.pipeline.StanfordCoreNLP$12.create(StanfordCoreNLP.java:603)
at edu.stanford.nlp.pipeline.StanfordCoreNLP$12.create(StanfordCoreNLP.java:585)
at edu.stanford.nlp.pipeline.AnnotatorPool.get(AnnotatorPool.java:62)
at edu.stanford.nlp.pipeline.StanfordCoreNLP.construct(StanfordCoreNLP.java:329)
at edu.stanford.nlp.pipeline.StanfordCoreNLP.(StanfordCoreNLP.java:196)
at edu.stanford.nlp.pipeline.StanfordCoreNLP.(StanfordCoreNLP.java:186)
at edu.stanford.nlp.pipeline.StanfordCoreNLP.(StanfordCoreNLP.java:178)
at Coref.main(Coref.java:41)

Answer 1

Yes, the L is just a bizarre Sun thing from ever since Java 1.0.

LexicalizedParser.loadModel(String, String ...) is a new method added to the parser, which is not being found. I suspect this means that you have another version of the parser in your classpath which is being used instead.

Try this: at the shell outside of any IDE, give these commands (giving the path to stanford-corenlp appropriately, and changing : to ; if on Windows:

javac -cp ".:stanford-corenlp-2012-04-09/*" Coref.java
java -mx3g -cp ".:stanford-corenlp-2012-04-09/*" Coref

The parser loads and your code runs correctly for me – just need to add some print statements so you can see what it has done :-).