/*
* Copyright 2002-2008 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.springframework.web.servlet.support;
import java.util.Locale;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.jstl.core.Config;
/**
* JSP-aware (and JSTL-aware) subclass of RequestContext, allowing for
* population of the context from a <code>javax.servlet.jsp.PageContext</code>.
*
* <p>This context will detect a JSTL locale attribute in page/request/session/application
* scope, in addition to the fallback locale strategy provided by the base class.
*
* @author Juergen Hoeller
* @since 1.1.4
* @see #getFallbackLocale
*/
public class JspAwareRequestContext extends RequestContext {
private PageContext pageContext;
/**
* Create a new JspAwareRequestContext for the given page context,
* using the request attributes for Errors retrieval.
* @param pageContext current JSP page context
*/
public JspAwareRequestContext(PageContext pageContext) {
initContext(pageContext, null);
}
/**
* Create a new JspAwareRequestContext for the given page context,
* using the given model attributes for Errors retrieval.
* @param pageContext current JSP page context
* @param model the model attributes for the current view
* (can be <code>null</code>, using the request attributes for Errors retrieval)
*/
public JspAwareRequestContext(PageContext pageContext, Map<String, Object> model) {
initContext(pageContext, model);
}
/**
* Initialize this context with the given page context,
* using the given model attributes for Errors retrieval.
* @param pageContext current JSP page context
* @param model the model attributes for the current view
* (can be <code>null</code>, using the request attributes for Errors retrieval)
*/
protected void initContext(PageContext pageContext, Map<String, Object> model) {
if (!(pageContext.getRequest() instanceof HttpServletRequest)) {
throw new IllegalArgumentException("RequestContext only supports HTTP requests");
}
this.pageContext = pageContext;
initContext((HttpServletRequest) pageContext.getRequest(), (HttpServletResponse) pageContext.getResponse(),
pageContext.getServletContext(), model);
}
/**
* Return the underlying PageContext.
* Only intended for cooperating classes in this package.
*/
protected final PageContext getPageContext() {
return this.pageContext;
}
/**
* This implementation checks for a JSTL locale attribute
* in page, request, session or application scope; if not found,
* returns the <code>HttpServletRequest.getLocale()</code>.
*/
@Override
protected Locale getFallbackLocale() {
if (jstlPresent) {
Locale locale = JstlPageLocaleResolver.getJstlLocale(getPageContext());
if (locale != null) {
return locale;
}
}
return getRequest().getLocale();
}
/**
* Inner class that isolates the JSTL dependency.
* Just called to resolve the fallback locale if the JSTL API is present.
*/
private static class JstlPageLocaleResolver {
public static Locale getJstlLocale(PageContext pageContext) {
Object localeObject = Config.find(pageContext, Config.FMT_LOCALE);
return (localeObject instanceof Locale ? (Locale) localeObject : null);
}
}
}
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