Zaval Java Resource Editor
A Catalogue of Free/Open Source Software for Translators
From the project's web-site:
The Zaval JRC Editor (also known as Zaval Java Resource Editor) solution is a small and easy-to-use visual editor for resource files.
Zaval Java Resource Editor is a way to manage closed source localization in Java. It is best used for regular access to various resource files. Our tool can handle resource bundle synchronization easily - it compares the files set and highlights all differences.