Q:

Java properties file editor for multiple lang.properties files? 

I have an application that reads a .properties file at start up containing key/values where the key is bound to an item in a file and the value is some text in the correct language (also determined at start up):
http://www.linuxtopia.org/online_books/eclipse_documentation/eclipse_birt_report_guide/topic/org.eclipse.birt.doc/birt/eclipse_birt_report_localization.20.1.html
Currently I need to support 3 languages and its a pain to maintain these 3 files since I need to make sure they always contain identical keys and translated values. 
Does there exist any good .properties file editors for this purpose that would make maintenance easier?  
It could be nice if an editor in the first column shows all the keys and in the following columns shows the language values (one column for each language). 

A:

You should give the Eclipse ResourceBundleEditor plugin a try. 

Lets you manage all localized properties files in one screen.  Some features: sorted keys, warning icons on missing keys/values, conversion to/from Unicode, hierarchical view of keys, more

