Auto-suggest and spellchecking support.
Packages 
Package Description
org.apache.lucene.search.spell
Suggest alternate spellings for words.
org.apache.lucene.search.suggest
Support for Autocomplete/Autosuggest
org.apache.lucene.search.suggest.analyzing
Analyzer based autosuggest.
org.apache.lucene.search.suggest.document
Support for document suggestion
org.apache.lucene.search.suggest.fst
Finite-state based autosuggest.
org.apache.lucene.search.suggest.tst
Ternary Search Tree based autosuggest.