Grails error message in Cinnamon Entitylib
Java Domain classes with JPA 1
Project: Cinnamon / Entitylib and AdminTool (Dandelion): cinnamon-cms.de
A normal call to load a GORM object (Java Domain class) fails with a strange error message:
java.lang.NullPointerException: Cannot invoke method isAssignableFrom() on null object at java_lang_Class$isAssignableFrom.call(Unknown Source) at eu.hornerproject.dandelion.IndexTypeController$_closure5.doCall(IndexTypeController.groovy:75) at eu.hornerproject.dandelion.IndexTypeController$_closure5.doCall(IndexTypeController.groovy
The code in question:
params.id contains a valid id.
The IndexType class is mapped.
Note that there is absolutely no hint as to what causes this problem - java.lang.Class is called from an unknown source, and stepping through to it by debugger is a quite impractical, because Grails / Groovy does so many things during the IndexType.get() step that you will probably die of old age before you find the problem.
(Probable) Cause & Solution
The IndexType class was missing getters and setters, and I guess the later ones are being used by GORM to set the indexerClass- and vaProvider-class fields.