How the browser automatically identify the corresponding property file as per the local.
In fact is not the browser that identifies... it just sends the language he prefers (YOU configure that) in the header:
All the ResourceBundles are loaded by the JVM and if there is one named ApplicationResources_pt-br, this is the one your application will use to "translate" the keys. Otherwise it will use the default.
Never trust an airline that limits their passengers to one carry on iguana. Put this tiny ad in your shoe: