/*
 * Copyright 2002-2017 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
 *
 *      https://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
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package org.springframework.web.servlet.support;

import java.util.Locale;
import java.util.ResourceBundle;
import java.util.TimeZone;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.jsp.jstl.core.Config;
import javax.servlet.jsp.jstl.fmt.LocalizationContext;

import org.springframework.context.MessageSource;
import org.springframework.context.support.MessageSourceResourceBundle;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.lang.Nullable;

Helper class for preparing JSTL views, in particular for exposing a JSTL localization context.
Author:Juergen Hoeller
Since:20.08.2003
/** * Helper class for preparing JSTL views, * in particular for exposing a JSTL localization context. * * @author Juergen Hoeller * @since 20.08.2003 */
public abstract class JstlUtils {
Checks JSTL's "javax.servlet.jsp.jstl.fmt.localizationContext" context-param and creates a corresponding child message source, with the provided Spring-defined MessageSource as parent.
Params:
  • servletContext – the ServletContext we're running in (to check JSTL-related context-params in web.xml)
  • messageSource – the MessageSource to expose, typically the ApplicationContext of the current DispatcherServlet
See Also:
Returns:the MessageSource to expose to JSTL; first checking the JSTL-defined bundle, then the Spring-defined MessageSource
/** * Checks JSTL's "javax.servlet.jsp.jstl.fmt.localizationContext" * context-param and creates a corresponding child message source, * with the provided Spring-defined MessageSource as parent. * @param servletContext the ServletContext we're running in * (to check JSTL-related context-params in {@code web.xml}) * @param messageSource the MessageSource to expose, typically * the ApplicationContext of the current DispatcherServlet * @return the MessageSource to expose to JSTL; first checking the * JSTL-defined bundle, then the Spring-defined MessageSource * @see org.springframework.context.ApplicationContext */
public static MessageSource getJstlAwareMessageSource( @Nullable ServletContext servletContext, MessageSource messageSource) { if (servletContext != null) { String jstlInitParam = servletContext.getInitParameter(Config.FMT_LOCALIZATION_CONTEXT); if (jstlInitParam != null) { // Create a ResourceBundleMessageSource for the specified resource bundle // basename in the JSTL context-param in web.xml, wiring it with the given // Spring-defined MessageSource as parent. ResourceBundleMessageSource jstlBundleWrapper = new ResourceBundleMessageSource(); jstlBundleWrapper.setBasename(jstlInitParam); jstlBundleWrapper.setParentMessageSource(messageSource); return jstlBundleWrapper; } } return messageSource; }
Exposes JSTL-specific request attributes specifying locale and resource bundle for JSTL's formatting and message tags, using Spring's locale and MessageSource.
Params:
  • request – the current HTTP request
  • messageSource – the MessageSource to expose, typically the current ApplicationContext (may be null)
See Also:
/** * Exposes JSTL-specific request attributes specifying locale * and resource bundle for JSTL's formatting and message tags, * using Spring's locale and MessageSource. * @param request the current HTTP request * @param messageSource the MessageSource to expose, * typically the current ApplicationContext (may be {@code null}) * @see #exposeLocalizationContext(RequestContext) */
public static void exposeLocalizationContext(HttpServletRequest request, @Nullable MessageSource messageSource) { Locale jstlLocale = RequestContextUtils.getLocale(request); Config.set(request, Config.FMT_LOCALE, jstlLocale); TimeZone timeZone = RequestContextUtils.getTimeZone(request); if (timeZone != null) { Config.set(request, Config.FMT_TIME_ZONE, timeZone); } if (messageSource != null) { LocalizationContext jstlContext = new SpringLocalizationContext(messageSource, request); Config.set(request, Config.FMT_LOCALIZATION_CONTEXT, jstlContext); } }
Exposes JSTL-specific request attributes specifying locale and resource bundle for JSTL's formatting and message tags, using Spring's locale and MessageSource.
Params:
  • requestContext – the context for the current HTTP request, including the ApplicationContext to expose as MessageSource
/** * Exposes JSTL-specific request attributes specifying locale * and resource bundle for JSTL's formatting and message tags, * using Spring's locale and MessageSource. * @param requestContext the context for the current HTTP request, * including the ApplicationContext to expose as MessageSource */
public static void exposeLocalizationContext(RequestContext requestContext) { Config.set(requestContext.getRequest(), Config.FMT_LOCALE, requestContext.getLocale()); TimeZone timeZone = requestContext.getTimeZone(); if (timeZone != null) { Config.set(requestContext.getRequest(), Config.FMT_TIME_ZONE, timeZone); } MessageSource messageSource = getJstlAwareMessageSource( requestContext.getServletContext(), requestContext.getMessageSource()); LocalizationContext jstlContext = new SpringLocalizationContext(messageSource, requestContext.getRequest()); Config.set(requestContext.getRequest(), Config.FMT_LOCALIZATION_CONTEXT, jstlContext); }
Spring-specific LocalizationContext adapter that merges session-scoped JSTL LocalizationContext/Locale attributes with the local Spring request context.
/** * Spring-specific LocalizationContext adapter that merges session-scoped * JSTL LocalizationContext/Locale attributes with the local Spring request context. */
private static class SpringLocalizationContext extends LocalizationContext { private final MessageSource messageSource; private final HttpServletRequest request; public SpringLocalizationContext(MessageSource messageSource, HttpServletRequest request) { this.messageSource = messageSource; this.request = request; } @Override public ResourceBundle getResourceBundle() { HttpSession session = this.request.getSession(false); if (session != null) { Object lcObject = Config.get(session, Config.FMT_LOCALIZATION_CONTEXT); if (lcObject instanceof LocalizationContext) { ResourceBundle lcBundle = ((LocalizationContext) lcObject).getResourceBundle(); return new MessageSourceResourceBundle(this.messageSource, getLocale(), lcBundle); } } return new MessageSourceResourceBundle(this.messageSource, getLocale()); } @Override public Locale getLocale() { HttpSession session = this.request.getSession(false); if (session != null) { Object localeObject = Config.get(session, Config.FMT_LOCALE); if (localeObject instanceof Locale) { return (Locale) localeObject; } } return RequestContextUtils.getLocale(this.request); } } }