Question

I read about properties and resource bundle. But I was unable to get difference between these. When to use Properties file and when to use Resource bundle.

To load properties file use the following code

Properties tempProp = new Properties();
FileInputStream propsFile = new FileInputStream(xyz.properties);
tempProp.load(propsFile);

To load Resource bundle

ResourceBundle labels =
    ResourceBundle.getBundle("xyz", currentLocale);
Enumeration bundleKeys = labels.getKeys();

In both of the cases (in resource bundle and in Properites) we are using properties file. The one difference I found is that to store application specific data we use properties file and to use i18n data we use resource bundle. I don’t know whether i am right or not.

I would like to know the use of the above two. What is the difference between these two.

Answer 1

Yes, you’re thinking along the right lines.

Resource bundles don’t have to use property files – it’s just one implementation (PropertyResourceBundle). A properties file is really just a string-to-string mapping – and that can be used for i18n, but doesn’t have to be.

ResourceBundle gives you a consistent way of requesting the appropriate object (usually a string) for a particular locale, with fallbacks etc. This is often, but not always, backed by a separate property file for each language.

So yes: if you’re dealing with i18n, you should use ResourceBundle; if you just need a string-to-string map persisted in a text file, it’s fine to use Properties directly.