[breaking] i18n - Introduced Messages.keys(Locale) allowing to list a…

…vailable Messages keys for a given Locale.

If you implemented your own Messages implementation, it will break your code : simply provide same implementation for keys(), without fixing the Locale.

restx-i18n/src/main/java/restx/i18n/DefaultMessages.java

@@ -55,11 +55,16 @@ public String getMessage(String key, MessageParams params, Locale locale) {
    }

    @Override
    public Iterable<String> keys() {
        Optional<ResourceBundle> bundle = getBundle(Locale.ROOT);
    public Iterable<String> keys(Locale locale) {
        Optional<ResourceBundle> bundle = getBundle(locale);
        return bundle.isPresent() ? Ordering.natural().sortedCopy(bundle.get().keySet()) : Collections.<String>emptySet();
    }

    @Override
    public Iterable<String> keys() {
        return keys(Locale.ROOT);
    }

    @Override
    public Iterable<Entry<String, String>> entries(Locale locale) {
        Optional<ResourceBundle> rootBundle = getBundle(Locale.ROOT);

restx-i18n/src/main/java/restx/i18n/Messages.java

@@ -8,6 +8,14 @@
 * an interpolation mechanism using a mustache like format, making it easier to use in Javascript client too.
 */
public interface Messages {
    /**
     * Return the list of message keys available in this Messages instance, for given Locale
     *
     * @param locale the locale in which the keys should be resolved.
     * @return the list of keys, as an Iterable
     */
    Iterable<String> keys(Locale locale);

    /**
     * Return the list of message keys available in this Messages instance.
     *