A resource bundle is a Java .properties file that contains locale-specific data.
Extracting locale-sensitive objects such as strings from the code (as opposed to hard-coding them) means that the application can handle multiple locales without having to write different code for each locale.
Therefore, using resource bundles improves the internationalisation and the localisation process of a software product.
In addition to these, translators can use any text editor to create new resource bundles or to modify existing ones.
The Message Compiler creates also constant definitions for the keys used to access the localized texts with the methods of the Java class ResourceBundle (6), ResourceBundle (7) and HTML documentation pages for each language.