[OPENNLP-1411] Provide equals and hashCode for POSModel

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.1.0
• Fix Version/s: 2.1.1
• Component/s: POS Tagger
• Assignee: Martin Wiesner
• Reporter: Martin Wiesner
• Created: 11/Dec/22 14:54
• Updated: 28/Jan/23 15:00
• Resolved: 14/Dec/22 13:39

Description

The test opennlp.tools.postag.POSModelTest signals by two TODOs that no actual assertions are made to check whether (de-)serialized POSModel instances are correctly read in again.

In other words: opennlp.tools.postag.POSModel lacks a valid equals/hashCode implementation by which one could verify a valid state (=equality) after (de-)serialization has occurred.

In addition, two possible base classes GISModel and PerceptronModel also require valid equals/hashCode implementations, so that POSModel's equals/hashCode will work properly.

Aim:

• Provide an improved implementation of the POS-related "Model" classes.
• Remove both TODOs in POSModelTest
• Improve both test cases (MaxEnt/GIS and Perceptron) with further test assertions.