This worked for me very well. And it doesn't reload the bundle everytime. I tried to take some stats to load and reload the bundle from external file location.
File file = new File("C:\\temp");
URL[] urls = {file.toURI().toURL()};
ClassLoader loader = new URLClassLoader(urls);
ResourceBundle rb = ResourceBundle.getBundle("myResource", Locale.getDefault(), loader);
where "c:\temp" is the external folder (NOT on the classpath) holding the property files, and "myResource" relates to myResource.properties, myResource_fr_FR.properties, etc.
Note: If you have the same bundle name on your classpath then it will be picked up by default using this constructor of URLClassLoader.
Credit to http://www.coderanch.com/t/432762/java/java/absolute-path-bundle-file
Find some of the stats below, all time in ms. I am not worried about the initial load time as that could be something with my workspace or code that I am trying to figure out but what I am trying to show is the reload took way lesser telling me its coming from memory.
Here some of the stats: