I'm not much of a Java guy, but would the available source for KeePassDroid be of any use? It looks like most of the DB stuff was implemented in Java with the crypto bits being handled by the NDK.

A flaw in code for handling Parquet, Apache’s open-source columnar data file format, allows attackers to run arbitrary code on vulnerable instances. The vulnerability, tracked as CVE-2025-30065, is a ...