stanfordnlp/CoreNLP · error · IllegalArgumentException

No model specified for Sentiment annotator

Error message

No model specified for Sentiment annotator

What it means

SentimentAnnotator's constructor resolves its model path from property '<name>.model' (e.g. sentiment.model) and falls back to DEFAULT_MODEL; if both are null it throws IllegalArgumentException because the sentiment classifier cannot be loaded without a trained model file.

Solutions

1. Set an explicit model path: -Dsentiment.model=edu/stanford/nlp/models/sentiment/sentiment.binary.gz.
2. Check for an empty-string override of sentiment.model in your properties or command line.
3. Verify the model file exists on the classpath or at the given filesystem path before constructing the pipeline.

Example fix

// before
Properties props = new Properties();
props.setProperty("annotators", "tokenize,ssplit,sentiment");
// after
props.setProperty("annotators", "tokenize,ssplit,sentiment");
props.setProperty("sentiment.model", "edu/stanford/nlp/models/sentiment/sentiment.binary.gz");

String model = props.getProperty("sentiment.model");
if (model == null || model.isEmpty()) {
  props.setProperty("sentiment.model", "edu/stanford/nlp/models/sentiment/sentiment.binary.gz");
}

try {
  SentimentAnnotator a = new SentimentAnnotator("sentiment", props);
} catch (IllegalArgumentException e) {
  if (e.getMessage().contains("No model specified")) {
    props.setProperty("sentiment.model", "edu/stanford/nlp/models/sentiment/sentiment.binary.gz");
    a = new SentimentAnnotator("sentiment", props);
  } else throw e;
}

When it happens

Trigger: Adding the 'sentiment' annotator to a pipeline with sentiment.model set to the empty string (getProperty returns "" only if set; null when neither property nor DEFAULT_MODEL exists, e.g. a build where DEFAULT_MODEL is null or the property value resolves to null via provider).

Common situations: Typos like sentiment.model pointing at a removed key, overriding properties through command-line -sentiment.model="", or distributions where the default model path resource is absent.

Understand the failure class

Background: "is required", "must be set", "missing required field": configuration validation errors across open-source libraries — this error's family across 36 libraries.

Related errors

• Invalid metric type for
• Invalid ordering constraint
• Cannot have these two ordering constraints
• Cannot have these two ordering constraints
• No input file specified!

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/80302c664eabd254. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/pipeline/SentimentAnnotator.java:59

  private static final String DEFAULT_MODEL = "edu/stanford/nlp/models/sentiment/sentiment.ser.gz";

  private final String modelPath;
  private final SentimentModel model;
  private final CollapseUnaryTransformer transformer = new CollapseUnaryTransformer();

  private final int nThreads;

  /**
   * Stop processing if we exceed this time limit, in milliseconds.
   * Use 0 for no limit.
   */
  private final long maxTime;

  public SentimentAnnotator(String annotatorName, Properties props) {
    this.modelPath = props.getProperty(annotatorName + ".model", DEFAULT_MODEL);
    if (modelPath == null) {
      throw new IllegalArgumentException("No model specified for Sentiment annotator");
    }
    this.model = SentimentModel.loadSerialized(modelPath);
    this.nThreads = PropertiesUtils.getInt(props, annotatorName + ".nthreads", PropertiesUtils.getInt(props, "nthreads", 1));
    this.maxTime = PropertiesUtils.getLong(props, annotatorName + ".maxtime", -1);
  }

  @Override
  public Set<Class<? extends CoreAnnotation>> requirementsSatisfied() {
    return Collections.emptySet();
  }

  @Override
  public Set<Class<? extends CoreAnnotation>> requires() {
    return Collections.unmodifiableSet(new ArraySet<>(Arrays.asList(
        CoreAnnotations.PartOfSpeechAnnotation.class,
        TreeCoreAnnotations.TreeAnnotation.class,
        TreeCoreAnnotations.BinarizedTreeAnnotation.class,
        CoreAnnotations.CategoryAnnotation.class

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