001/*
002 * Copyright 2002-2017 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.servlet.support;
018
019import java.util.Locale;
020import java.util.Map;
021import java.util.TimeZone;
022import javax.servlet.http.HttpServletRequest;
023import javax.servlet.http.HttpServletResponse;
024import javax.servlet.jsp.PageContext;
025import javax.servlet.jsp.jstl.core.Config;
026
027/**
028 * JSP-aware (and JSTL-aware) subclass of RequestContext, allowing for
029 * population of the context from a {@code javax.servlet.jsp.PageContext}.
030 *
031 * <p>This context will detect a JSTL locale attribute in page/request/session/application
032 * scope, in addition to the fallback locale strategy provided by the base class.
033 *
034 * @author Juergen Hoeller
035 * @since 1.1.4
036 * @see #getFallbackLocale
037 */
038public class JspAwareRequestContext extends RequestContext {
039
040        private PageContext pageContext;
041
042
043        /**
044         * Create a new JspAwareRequestContext for the given page context,
045         * using the request attributes for Errors retrieval.
046         * @param pageContext current JSP page context
047         */
048        public JspAwareRequestContext(PageContext pageContext) {
049                initContext(pageContext, null);
050        }
051
052        /**
053         * Create a new JspAwareRequestContext for the given page context,
054         * using the given model attributes for Errors retrieval.
055         * @param pageContext current JSP page context
056         * @param model the model attributes for the current view
057         * (can be {@code null}, using the request attributes for Errors retrieval)
058         */
059        public JspAwareRequestContext(PageContext pageContext, Map<String, Object> model) {
060                initContext(pageContext, model);
061        }
062
063        /**
064         * Initialize this context with the given page context,
065         * using the given model attributes for Errors retrieval.
066         * @param pageContext current JSP page context
067         * @param model the model attributes for the current view
068         * (can be {@code null}, using the request attributes for Errors retrieval)
069         */
070        protected void initContext(PageContext pageContext, Map<String, Object> model) {
071                if (!(pageContext.getRequest() instanceof HttpServletRequest)) {
072                        throw new IllegalArgumentException("RequestContext only supports HTTP requests");
073                }
074                this.pageContext = pageContext;
075                initContext((HttpServletRequest) pageContext.getRequest(), (HttpServletResponse) pageContext.getResponse(),
076                                pageContext.getServletContext(), model);
077        }
078
079
080        /**
081         * Return the underlying PageContext.
082         * Only intended for cooperating classes in this package.
083         */
084        protected final PageContext getPageContext() {
085                return this.pageContext;
086        }
087
088        /**
089         * This implementation checks for a JSTL locale attribute in page,
090         * request, session or application scope; if not found, returns the
091         * {@code HttpServletRequest.getLocale()}.
092         */
093        @Override
094        protected Locale getFallbackLocale() {
095                if (jstlPresent) {
096                        Locale locale = JstlPageLocaleResolver.getJstlLocale(getPageContext());
097                        if (locale != null) {
098                                return locale;
099                        }
100                }
101                return getRequest().getLocale();
102        }
103
104        /**
105         * This implementation checks for a JSTL time zone attribute in page,
106         * request, session or application scope; if not found, returns {@code null}.
107         */
108        @Override
109        protected TimeZone getFallbackTimeZone() {
110                if (jstlPresent) {
111                        TimeZone timeZone = JstlPageLocaleResolver.getJstlTimeZone(getPageContext());
112                        if (timeZone != null) {
113                                return timeZone;
114                        }
115                }
116                return null;
117        }
118
119
120        /**
121         * Inner class that isolates the JSTL dependency.
122         * Just called to resolve the fallback locale if the JSTL API is present.
123         */
124        private static class JstlPageLocaleResolver {
125
126                public static Locale getJstlLocale(PageContext pageContext) {
127                        Object localeObject = Config.find(pageContext, Config.FMT_LOCALE);
128                        return (localeObject instanceof Locale ? (Locale) localeObject : null);
129                }
130
131                public static TimeZone getJstlTimeZone(PageContext pageContext) {
132                        Object timeZoneObject = Config.find(pageContext, Config.FMT_TIME_ZONE);
133                        return (timeZoneObject instanceof TimeZone ? (TimeZone) timeZoneObject : null);
134                }
135        }
136
137}