opennlp.tools.ngram

## Class NGramGenerator

- java.lang.Object
- - opennlp.tools.ngram.NGramGenerator

-     public class NGramGenerator
      extends Object

  Generates an nGram, with optional separator, and returns the grams as a list of strings

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `NGramGenerator()`

  - ### Method Summary

    All Methods Static Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `static List<String>` | `generate(char[] input, int n, String separator)` Generates an nGram based on a char[] input
    `static List<String>` | `generate(List<String> input, int n, String separator)` Creates an ngram separated by the separator param value i.e.

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### NGramGenerator

          public NGramGenerator()

  - ### Method Detail

    - #### generate

          public static List<String> generate(List<String> input,
                                              int n,
                                              String separator)

      Creates an ngram separated by the separator param value i.e. a,b,c,d with n = 3 and separator = "-" would return a-b-c,b-c-d
      Parameters:
        `input` - the input tokens the output ngrams will be derived from
        `n` - the number of tokens as the sliding window
        `separator` - each string in each gram will be separated by this value if desired. Pass in empty string if no separator is desired
      Returns:

    - #### generate

          public static List<String> generate(char[] input,
                                              int n,
                                              String separator)

      Generates an nGram based on a char[] input
      Parameters:
        `input` - the array of chars to convert to nGram
        `n` - The number of grams (chars) that each output gram will consist of
        `separator` - each char in each gram will be separated by this value if desired. Pass in empty string if no separator is desired
      Returns:

Copyright © 2026 The Apache Software Foundation. All rights reserved.