How can I index and search digits and other non-alphabetic characters?

Otis Gospodnetic

The components responsible for this are various Analyzers.
The demos included in Lucene distribution use StopAnalyzer, which filters out non-alphabetic characters. To include non-alphabetic characters, such as digits and various punctuation characters in your index use org.apache.lucene.analysis.standard.StandardAnalyzer instead of StopAnalyzer