Getting the error while integrating stanford sentiment analysis with java

Question

I am working on sentiment analysis using stanford sentiment nlp library with java. But when I am executing the code I am getting the error. Not able to figure it out.

My code is as follows:

package com.nlp;

 import java.util.Properties;
 import edu.stanford.nlp.ling.CoreAnnotations;
 import edu.stanford.nlp.pipeline.Annotation;
 import edu.stanford.nlp.pipeline.StanfordCoreNLP;
 import edu.stanford.nlp.rnn.RNNCoreAnnotations;
 import edu.stanford.nlp.sentiment.SentimentCoreAnnotations;
 import edu.stanford.nlp.trees.Tree;
 import edu.stanford.nlp.util.CoreMap;

 public class SemanticAnalysis {
    public static void main(String args[]) {
        sentimentAnalysis sentiment = new sentimentAnalysis();
        sentiment.findSentiment("france is a good city");
    }   
 }

 class sentimentAnalysis {
     public String findSentiment(String line) {

        Properties props = new Properties();
        props.setProperty("annotators", "tokenize, ssplit, parse, sentiment");
        StanfordCoreNLP pipeline = new StanfordCoreNLP(props);
        int mainSentiment = 0;
        if (line != null && line.length() > 0) {
            int longest = 0;
            Annotation annotation = pipeline.process(line);
           for (CoreMap sentence :annotation.get( CoreAnnotations.SentencesAnnotation.class )) {
                Tree tree = sentence.get(SentimentCoreAnnotations.AnnotatedTree.class);
                int sentiment = RNNCoreAnnotations.getPredictedClass(tree);
                String partText = sentence.toString();
                if (partText.length() > longest) {
                    mainSentiment = sentiment;
                    longest = partText.length();
                } 
            }
        }
        if (mainSentiment == 2 || mainSentiment > 4 || mainSentiment < 0) {
            return null;
        }
        return "";
     }
 }

But when i am running the code i am getting the following error.

   Exception in thread "main" java.lang.NoClassDefFoundError: org/ejml/simple/SimpleBase
at edu.stanford.nlp.pipeline.SentimentAnnotator.<init>(SentimentAnnotator.java:45)
at edu.stanford.nlp.pipeline.StanfordCoreNLP$14.create(StanfordCoreNLP.java:845)
at edu.stanford.nlp.pipeline.AnnotatorPool.get(AnnotatorPool.java:81)  

Answer 1

你缺少ejml-0.23.jar，将它添加到你的类路径，它应该工作。

Answer 2

You are missing the reference to Efficient Java Matrix Library (EJML) in your classpath .

BTW. Try to split your code into smaller single task methods to get more clear code.

class SentimentAnalysis {

     public String findSentiment(String line) {

        if(line == null || line.isEmpty()) {
          throw new IllegalArgumentException("The line must not be null or empty.");
        }

        Annotation annotation = processLine(line);

        int mainSentiment = findMainSentiment(annotation);

        if(mainSentiment < 0 || mainSentiment == 2 || mainSentiment > 4) { //You should avoid magic numbers like 2 or 4 try to create a constant that will provide a description why 2
           return null; //You shold avoid null returns 
        }

        return "";

     }


     private int findMainSentiment(Annotation annotation) {

        int mainSentiment = Integer.MIN_VALUE;
        int longest = Integer.MIN_VALUE;


        for (CoreMap sentence : annotation.get(CoreAnnotations.SentencesAnnotation.class)) {

           int sentenceLength = String.valueOf(sentence).length();

           if(sentenceLength > longest) {

             Tree tree = sentence.get(SentimentCoreAnnotations.AnnotatedTree.class);

             mainSentiment = RNNCoreAnnotations.getPredictedClass(tree);

             longest = sentenceLength ;

            }
        }

        return mainSentiment;

     }


     private Annotation processLine(String line) {

        StanfordCoreNLP pipeline = createPieline();

        return pipeline.process(line);

     }

     private StanfordCoreNLP createPieline() {

        Properties props = createPipelineProperties();

        StanfordCoreNLP pipeline = new StanfordCoreNLP(props);

        return pipeline;

     }

     private Properties createPipelieProperties() {

        Properties props = new Properties();
        props.setProperty("annotators", "tokenize, ssplit, parse, sentiment");

        return props;

     }


 }

Answer 3

I was getting same error and I added all the jar files and the code got executed. Then I found out by removing one-one jar file and running the code and answer was add the following files.

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