Aperture is a Java framework for extracting and querying full-text content and metadata from various information systems (e.g. file systems, web sites, mail boxes) and the file formats (e.g. documents, images) occurring in these systems.
Sommer is a very simple library for mapping Plain Old Java Objects (POJOs) to RDF graphs and back. Sommer stands for "Semantic Object (Metadata) MappeR".