i18n - Caching resolved Messages keys for a given Locale, avoiding to…

… rely on a complicated ResourceBundle resolution when retrieving Messages keys

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

@@ -1,6 +1,9 @@
package restx.i18n;

import com.google.common.base.Optional;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.Ordering;
import com.google.common.io.Resources;
import com.samskivert.mustache.Mustache;
@@ -31,6 +34,13 @@
public class DefaultMessages extends AbstractMessages implements Messages {
    private final String baseName;
    private final Charset charset;
    private final LoadingCache<Locale, Iterable<String>> cachedKeysByLocale = CacheBuilder.newBuilder().build(new CacheLoader<Locale, Iterable<String>>() {
        @Override
        public Iterable<String> load(Locale locale) throws Exception {
            Optional<ResourceBundle> bundle = getBundle(locale);
            return bundle.isPresent() ? Ordering.natural().sortedCopy(bundle.get().keySet()) : Collections.<String>emptySet();
        }
    });

    public DefaultMessages(String baseName) {
        this(baseName, StandardCharsets.UTF_8);
@@ -56,8 +66,11 @@ public String getMessage(String key, MessageParams params, Locale locale) {

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

    protected void invalidateCachedKeysFor(Locale locale) {
        cachedKeysByLocale.invalidate(locale);
    }

    @Override

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

@@ -32,6 +32,7 @@ public MutableMessages setMessageTemplate(String key, String messageTemplate, Lo
        }
        MutablePropertyResourceBundle bundle = (MutablePropertyResourceBundle) b.get();
        bundle.setMessageTemplate(key, messageTemplate);
        invalidateCachedKeysFor(locale);
        return this;
    }