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/* * Copyright 2002-2019 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 * limitations under the License. */ package org.springframework.web.servlet.i18n; import java.util.Locale; import java.util.TimeZone; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.context.i18n.LocaleContext; import org.springframework.context.i18n.SimpleLocaleContext; import org.springframework.context.i18n.TimeZoneAwareLocaleContext; import org.springframework.lang.Nullable; import org.springframework.util.Assert; import org.springframework.util.StringUtils; import org.springframework.web.servlet.LocaleContextResolver; import org.springframework.web.servlet.LocaleResolver; import org.springframework.web.util.CookieGenerator; import org.springframework.web.util.WebUtils; /** * {@link LocaleResolver} implementation that uses a cookie sent back to the user * in case of a custom setting, with a fallback to the specified default locale * or the request's accept-header locale. * * <p>This is particularly useful for stateless applications without user sessions. * The cookie may optionally contain an associated time zone value as well; * alternatively, you may specify a default time zone. * * <p>Custom controllers can override the user's locale and time zone by calling * {@code #setLocale(Context)} on the resolver, e.g. responding to a locale change * request. As a more convenient alternative, consider using * {@link org.springframework.web.servlet.support.RequestContext#changeLocale}. * * @author Juergen Hoeller * @author Jean-Pierre Pawlak * @since 27.02.2003 * @see #setDefaultLocale * @see #setDefaultTimeZone */ public class CookieLocaleResolver extends CookieGenerator implements LocaleContextResolver { /** * The name of the request attribute that holds the {@code Locale}. * <p>Only used for overriding a cookie value if the locale has been * changed in the course of the current request! * <p>Use {@code RequestContext(Utils).getLocale()} * to retrieve the current locale in controllers or views. * @see org.springframework.web.servlet.support.RequestContext#getLocale * @see org.springframework.web.servlet.support.RequestContextUtils#getLocale */ public static final String LOCALE_REQUEST_ATTRIBUTE_NAME = CookieLocaleResolver.class.getName() + ".LOCALE"; /** * The name of the request attribute that holds the {@code TimeZone}. * <p>Only used for overriding a cookie value if the locale has been * changed in the course of the current request! * <p>Use {@code RequestContext(Utils).getTimeZone()} * to retrieve the current time zone in controllers or views. * @see org.springframework.web.servlet.support.RequestContext#getTimeZone * @see org.springframework.web.servlet.support.RequestContextUtils#getTimeZone */ public static final String TIME_ZONE_REQUEST_ATTRIBUTE_NAME = CookieLocaleResolver.class.getName() + ".TIME_ZONE"; /** * The default cookie name used if none is explicitly set. */ public static final String DEFAULT_COOKIE_NAME = CookieLocaleResolver.class.getName() + ".LOCALE"; private boolean languageTagCompliant = true; private boolean rejectInvalidCookies = true; @Nullable private Locale defaultLocale; @Nullable private TimeZone defaultTimeZone; /** * Create a new instance of the {@link CookieLocaleResolver} class * using the {@link #DEFAULT_COOKIE_NAME default cookie name}. */ public CookieLocaleResolver() { setCookieName(DEFAULT_COOKIE_NAME); } /** * Specify whether this resolver's cookies should be compliant with BCP 47 * language tags instead of Java's legacy locale specification format. * <p>The default is {@code true}, as of 5.1. Switch this to {@code false} * for rendering Java's legacy locale specification format. For parsing, * this resolver leniently accepts the legacy {@link Locale#toString} * format as well as BCP 47 language tags in any case. * @since 4.3 * @see #parseLocaleValue(String) * @see #toLocaleValue(Locale) * @see Locale#forLanguageTag(String) * @see Locale#toLanguageTag() */ public void setLanguageTagCompliant(boolean languageTagCompliant) { this.languageTagCompliant = languageTagCompliant; } /** * Return whether this resolver's cookies should be compliant with BCP 47 * language tags instead of Java's legacy locale specification format. * @since 4.3 */ public boolean isLanguageTagCompliant() { return this.languageTagCompliant; } /** * Specify whether to reject cookies with invalid content (e.g. invalid format). * <p>The default is {@code true}. Turn this off for lenient handling of parse * failures, falling back to the default locale and time zone in such a case. * @since 5.1.7 * @see #setDefaultLocale * @see #setDefaultTimeZone * @see #determineDefaultLocale * @see #determineDefaultTimeZone */ public void setRejectInvalidCookies(boolean rejectInvalidCookies) { this.rejectInvalidCookies = rejectInvalidCookies; } /** * Return whether to reject cookies with invalid content (e.g. invalid format). * @since 5.1.7 */ public boolean isRejectInvalidCookies() { return this.rejectInvalidCookies; } /** * Set a fixed locale that this resolver will return if no cookie found. */ public void setDefaultLocale(@Nullable Locale defaultLocale) { this.defaultLocale = defaultLocale; } /** * Return the fixed locale that this resolver will return if no cookie found, * if any. */ @Nullable protected Locale getDefaultLocale() { return this.defaultLocale; } /** * Set a fixed time zone that this resolver will return if no cookie found. * @since 4.0 */ public void setDefaultTimeZone(@Nullable TimeZone defaultTimeZone) { this.defaultTimeZone = defaultTimeZone; } /** * Return the fixed time zone that this resolver will return if no cookie found, * if any. * @since 4.0 */ @Nullable protected TimeZone getDefaultTimeZone() { return this.defaultTimeZone; } @Override public Locale resolveLocale(HttpServletRequest request) { parseLocaleCookieIfNecessary(request); return (Locale) request.getAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME); } @Override public LocaleContext resolveLocaleContext(final HttpServletRequest request) { parseLocaleCookieIfNecessary(request); return new TimeZoneAwareLocaleContext() { @Override @Nullable public Locale getLocale() { return (Locale) request.getAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME); } @Override @Nullable public TimeZone getTimeZone() { return (TimeZone) request.getAttribute(TIME_ZONE_REQUEST_ATTRIBUTE_NAME); } }; } private void parseLocaleCookieIfNecessary(HttpServletRequest request) { if (request.getAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME) == null) { Locale locale = null; TimeZone timeZone = null; // Retrieve and parse cookie value. String cookieName = getCookieName(); if (cookieName != null) { Cookie cookie = WebUtils.getCookie(request, cookieName); if (cookie != null) { String value = cookie.getValue(); String localePart = value; String timeZonePart = null; int separatorIndex = localePart.indexOf('/'); if (separatorIndex == -1) { // Leniently accept older cookies separated by a space... separatorIndex = localePart.indexOf(' '); } if (separatorIndex >= 0) { localePart = value.substring(0, separatorIndex); timeZonePart = value.substring(separatorIndex + 1); } try { locale = (!"-".equals(localePart) ? parseLocaleValue(localePart) : null); if (timeZonePart != null) { timeZone = StringUtils.parseTimeZoneString(timeZonePart); } } catch (IllegalArgumentException ex) { if (isRejectInvalidCookies() && request.getAttribute(WebUtils.ERROR_EXCEPTION_ATTRIBUTE) == null) { throw new IllegalStateException("Encountered invalid locale cookie '" + cookieName + "': [" + value + "] due to: " + ex.getMessage()); } else { // Lenient handling (e.g. error dispatch): ignore locale/timezone parse exceptions if (logger.isDebugEnabled()) { logger.debug("Ignoring invalid locale cookie '" + cookieName + "': [" + value + "] due to: " + ex.getMessage()); } } } if (logger.isTraceEnabled()) { logger.trace("Parsed cookie value [" + cookie.getValue() + "] into locale '" + locale + "'" + (timeZone != null ? " and time zone '" + timeZone.getID() + "'" : "")); } } } request.setAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME, (locale != null ? locale : determineDefaultLocale(request))); request.setAttribute(TIME_ZONE_REQUEST_ATTRIBUTE_NAME, (timeZone != null ? timeZone : determineDefaultTimeZone(request))); } } @Override public void setLocale(HttpServletRequest request, @Nullable HttpServletResponse response, @Nullable Locale locale) { setLocaleContext(request, response, (locale != null ? new SimpleLocaleContext(locale) : null)); } @Override public void setLocaleContext(HttpServletRequest request, @Nullable HttpServletResponse response, @Nullable LocaleContext localeContext) { Assert.notNull(response, "HttpServletResponse is required for CookieLocaleResolver"); Locale locale = null; TimeZone timeZone = null; if (localeContext != null) { locale = localeContext.getLocale(); if (localeContext instanceof TimeZoneAwareLocaleContext) { timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone(); } addCookie(response, (locale != null ? toLocaleValue(locale) : "-") + (timeZone != null ? '/' + timeZone.getID() : "")); } else { removeCookie(response); } request.setAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME, (locale != null ? locale : determineDefaultLocale(request))); request.setAttribute(TIME_ZONE_REQUEST_ATTRIBUTE_NAME, (timeZone != null ? timeZone : determineDefaultTimeZone(request))); } /** * Parse the given locale value coming from an incoming cookie. * <p>The default implementation calls {@link StringUtils#parseLocale(String)}, * accepting the {@link Locale#toString} format as well as BCP 47 language tags. * @param localeValue the locale value to parse * @return the corresponding {@code Locale} instance * @since 4.3 * @see StringUtils#parseLocale(String) */ @Nullable protected Locale parseLocaleValue(String localeValue) { return StringUtils.parseLocale(localeValue); } /** * Render the given locale as a text value for inclusion in a cookie. * <p>The default implementation calls {@link Locale#toString()} * or JDK 7's {@link Locale#toLanguageTag()}, depending on the * {@link #setLanguageTagCompliant "languageTagCompliant"} configuration property. * @param locale the locale to stringify * @return a String representation for the given locale * @since 4.3 * @see #isLanguageTagCompliant() */ protected String toLocaleValue(Locale locale) { return (isLanguageTagCompliant() ? locale.toLanguageTag() : locale.toString()); } /** * Determine the default locale for the given request, * Called if no locale cookie has been found. * <p>The default implementation returns the specified default locale, * if any, else falls back to the request's accept-header 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() */ @Nullable protected Locale determineDefaultLocale(HttpServletRequest request) { Locale defaultLocale = getDefaultLocale(); if (defaultLocale == null) { defaultLocale = request.getLocale(); } return defaultLocale; } /** * Determine the default time zone for the given request, * Called if no time zone cookie has been found. * <p>The default implementation returns the specified default time zone, * if any, or {@code null} otherwise. * @param request the request to resolve the time zone for * @return the default time zone (or {@code null} if none defined) * @see #setDefaultTimeZone */ @Nullable protected TimeZone determineDefaultTimeZone(HttpServletRequest request) { return getDefaultTimeZone(); } }