How to use the chunker Java ?

[Ben Rhelp]

Hi all,

I am trying to find out how to use the Java API for the chunker.

Below is the console output of my failed attempt (My test program is further 
down in the body of this email). 


Any idea on what I am doing wrong?


thanks in advance,

Ben


Console output:

------------------------------------
Token    Part-Of-Speech
Most    JJS
large    JJ
cities    NNS
in    IN
the    DT
US    NNP
had    VBD
morning    NN
and    CC
afternoon    NN
newspapers    NNS
.    .
opennlp.tools.util.InvalidFormatException: Unkown artifact format: postagger
    at opennlp.tools.util.model.BaseModel.<init>(BaseModel.java:132)
    at opennlp.tools.chunker.ChunkerModel.<init>(ChunkerModel.java:60)
    at ChunkerTest.main(ChunkerTest.java:55)
Exception in thread "main" java.lang.NullPointerException
    at opennlp.tools.chunker.ChunkerME.<init>(ChunkerME.java:77)
    at opennlp.tools.chunker.ChunkerME.<init>(ChunkerME.java:93)
    at opennlp.tools.chunker.ChunkerME.<init>(ChunkerME.java:106)
    at opennlp.tools.chunker.ChunkerME.<init>(ChunkerME.java:116)
    at ChunkerTest.main(ChunkerTest.java:71)



My test program:

import opennlp.tools.postag.POSModel;
import opennlp.tools.postag.POSTaggerME;
import opennlp.tools.chunker.ChunkerModel;
import opennlp.tools.chunker.ChunkerME;

import java.io.*;

public class ChunkerTest {
    
    private static final String POSTAGGER = 
"C:\\Users\\Ben\\Desktop\\BenSave\\NPLmodels\\en-pos-maxent.bin";
    private static final String CHUNKER = 
"C:\\Users\\Ben\\Desktop\\BenSave\\NPLmodels\\en-parser-chunking.bin"; 
    
public static void main(String[] args) throws IOException {
    InputStream modelIn4 = null;
    POSModel modelPostTagger = null;

    try {
      modelIn4 = new FileInputStream(POSTAGGER);
      modelPostTagger = new POSModel(modelIn4);
    }
    catch (IOException e) {
      // Model loading failed, handle the error
      e.printStackTrace();
    }
    finally {
      if (modelIn4 != null) {
        try {
          modelIn4.close();
        }
        catch (IOException e) {
        }
      }
    }

    POSTaggerME myTagger = new POSTaggerME(modelPostTagger);
    
    String sent[] = new String[]{"Most", "large", "cities", "in", "the", "US", 
"had",
            "morning", "and", "afternoon", "newspapers", "."};          
    String tags1[] = myTagger.tag(sent);
    

    System.out.println("------------------------------------");
    System.out.println("Token\tPart-Of-Speech");
    for (int i=0; i < tags1.length;i++) {
        System.out.println(sent[i]+"\t"+tags1[i]);
    }
    

    /*---------------------------------------------------------*/
    
    InputStream modelIn5 = new FileInputStream(CHUNKER);
    ChunkerModel modelChunker = null;

    try {
        modelChunker = new ChunkerModel(modelIn5); 
    }
    catch (IOException e) {
      // Model loading failed, handle the error
      e.printStackTrace();
    }
    finally {
      if (modelIn5 != null) {
        try {
          modelIn5.close();
        }
        catch (IOException e) {
        }
      }
    }
    
    ChunkerME chunker = new ChunkerME(modelChunker);
    
    String tags2[] = chunker.chunk(sent, tags1);
    
    System.out.println("------------------------------------");
    System.out.println("Token\tPart-Of-Speech\tChunks");
    for (int i=0; i < tags2.length;i++) {
        System.out.println(sent[i]+"\t"+tags1[i]+"\t"+tags2[i]);
    }
    System.out.println("------------------------------------");
}

}