jodd-core/src/main/java/jodd/util/ResourceBundleMessageResolver.java
public ResourceBundle findResourceBundle(String bundleName, Locale locale) {
		if (bundleName == null) {
			bundleName = fallbackBundlename;
		}
		if (locale == null) {
			locale = fallbackLocale;
		}
		if (!cacheResourceBundles) {
			try {
				return getBundle(bundleName, locale, ClassLoaderUtil.getDefaultClassLoader());
			} catch (MissingResourceException ignore) {
				return null;
			}
		}
		String key = bundleName + '_' + locale.toLanguageTag();
		try {
			if (!misses.contains(key)) {
				ResourceBundle bundle = notmisses.get(key);
				if (bundle == null) {
					bundle = getBundle(bundleName, locale, ClassLoaderUtil.getDefaultClassLoader());
					notmisses.put(key, bundle);
				}
				return bundle;
			}
		} catch (MissingResourceException ignore) {
			misses.add(key);
		}
		return null;
	}
public ResourceBundle findResourceBundle(String bundleName, Locale locale) {
		if (bundleName == null) {
			bundleName = fallbackBundlename;
		}
		if (locale == null) {
			locale = fallbackLocale;
		}
		if (!cacheResourceBundles) {
			try {
				return getBundle(bundleName, locale, ClassLoaderUtil.getDefaultClassLoader());
			} catch (MissingResourceException ignore) {
				return null;
			}
		}
		String key = bundleName + '_' + locale.toLanguageTag();
		try {
			if (!misses.contains(key)) {
				ResourceBundle bundle = notmisses.get(key);
				if (bundle == null) {
					bundle = getBundle(bundleName, locale, ClassLoaderUtil.getDefaultClassLoader());
					notmisses.put(key, bundle);
				}
				return bundle;
			}
		} catch (MissingResourceException ignore) {
			misses.add(key);
		}
		return null;
	}
Finds resource bundle by it's name. Missed and founded resource bundles are cached for
better performances. Returns <code>null</code> if resource bundle is missing.