Book Image

Natural Language Processing with Java

By : Richard M. Reese , Richard M Reese
Book Image

Natural Language Processing with Java

By: Richard M. Reese , Richard M Reese

Overview of this book

Table of Contents (15 chapters)
Natural Language Processing with Java
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

NLP tokenizer APIs


In this section, we will demonstrate several different tokenization techniques using the OpenNLP, Stanford, and LingPipe APIs. Although there are a number of other APIs available, we restricted the demonstration to these APIs. The examples will give you an idea of what techniques are available.

We will use a string called paragraph to illustrate these techniques. The string includes a new line break that may occur in real text in unexpected places. It is defined here:

private String paragraph = "Let's pause, \nand then ++ "reflect.";

Using the OpenNLPTokenizer class

OpenNLP possesses a Tokenizer interface that is implemented by three classes: SimpleTokenizer, TokenizerME, and WhitespaceTokenizer. This interface supports two methods:

  • tokenize: This is passed a string to tokenize and returns an array of tokens as strings.

  • tokenizePos: This is passed a string and returns an array of Span objects. The Span class is used to specify the beginning and ending offsets of the tokens...