A more reasonable SessionLocaleResolver

src/main/java/org/genesys2/spring/BetterSessionLocaleResolver.java

+/*
+ * Copyright 2002-2012 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.genesys2.spring;
+
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Set;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.web.servlet.i18n.SessionLocaleResolver;
+
+/**
+ * Implementation of LocaleResolver that uses a locale attribute in the user's
+ * session in case of a custom setting, with a fallback to the specified default
+ * locale or the request's accept-header locale.
+ * 
+ * <p>
+ * This is most appropriate if the application needs user sessions anyway, that
+ * is, when the HttpSession does not have to be created for the locale.
+ * 
+ * <p>
+ * Custom controllers can override the user's locale by calling
+ * {@code setLocale}, e.g. responding to a locale change request.
+ * 
+ * @author Juergen Hoeller
+ * @author Matija Obreza
+ * 
+ * @see #setDefaultLocale
+ * @see #setLocale
+ */
+public class BetterSessionLocaleResolver extends SessionLocaleResolver {
+
+	private Set<String> supportedLocales = new HashSet<String>();
+
+	public void setSupportedLocales(Set<String> supportedLocales) {
+		this.supportedLocales = supportedLocales;
+	}
+
+	public Set<String> getSupportedLocales() {
+		return supportedLocales;
+	}
+
+	/**
+	 * Determine the default locale for the given request, Called if no locale
+	 * session attribute has been found.
+	 * <p>
+	 * This implementation returns the request's accept-header locale if listed
+	 * in the {@link #supportedLocales} , else falls back to the specified
+	 * default locale.
+	 * 
+	 * @param request
+	 *            the request to resolve the locale for
+	 * @return the default locale (never {@code null})
+	 * @see #setDefaultLocale
+	 * @see javax.servlet.http.HttpServletRequest#getLocale()
+	 */
+	protected Locale determineDefaultLocale(HttpServletRequest request) {
+		Locale defaultLocale = request.getLocale();
+
+		if (defaultLocale != null && !supportedLocales.contains(defaultLocale.getLanguage())) {
+			// reset request locale if not on the list of supported locales
+			defaultLocale = null;
+		}
+
+		if (defaultLocale == null) {
+			defaultLocale = getDefaultLocale();
+		}
+		return defaultLocale;
+	}
+
+}

src/main/resources/spring/servlet.xml

@@ -95,8 +95,16 @@
     </mvc:interceptors>
 
     <!--Locale resolver-->
-    <bean name="localeResolver" class="org.springframework.web.servlet.i18n.SessionLocaleResolver">
+    <bean name="localeResolver" class="org.genesys2.spring.BetterSessionLocaleResolver">
         <property name="defaultLocale" value="en"/>
+        <property name="supportedLocales">
+        	<set>
+        		<value>en</value>
+        		<value>es</value>
+        		<value>fa</value>
+        		<!-- <value>sl</value> -->
+        	</set>
+        </property>
     </bean>
 
 </beans>