I use a @AnalyzerDiscriminator in order to return the name of an existing analyzer depending on the language out of my Analzyers defined in @AnalyzerDefs. Further on I use a custom Field extending AbstractField/implementing org.apache.lucene.document.Fieldable within a custom FieldBridge. On building the corresponding index I then do get a ClassCastException from ocumentBuilderIndexedEntity's allowAnalyzerDiscriminatorOverride() method because this method casts the document's fields retrieved with doc.getFields() to Field instead of Fieldable even though Fieldable interface implementing objects are only added to that list in Document! Thus Fieldable interface should rather be used here instead of Field.