/**
 * Change the current locale to the specified locale and time zone context,
 * storing the new locale context through the configured {@link LocaleResolver}.
 * @param locale the new locale
 * @param timeZone the new time zone
 * @see LocaleContextResolver#setLocaleContext
 * @see org.springframework.context.i18n.SimpleTimeZoneAwareLocaleContext
 */
public void changeLocale(Locale locale, TimeZone timeZone) {
	LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(this.request);
	if (!(localeResolver instanceof LocaleContextResolver)) {
		throw new IllegalStateException("Cannot change locale context if no LocaleContextResolver configured");
	}
	((LocaleContextResolver) localeResolver).setLocaleContext(this.request, this.response,
			new SimpleTimeZoneAwareLocaleContext(locale, timeZone));
	this.locale = locale;
	this.timeZone = timeZone;
}
 

/**
 * Change the current locale to the specified locale and time zone context,
 * storing the new locale context through the configured {@link LocaleResolver}.
 * @param locale the new locale
 * @param timeZone the new time zone
 * @see LocaleContextResolver#setLocaleContext
 * @see org.springframework.context.i18n.SimpleTimeZoneAwareLocaleContext
 */
public void changeLocale(Locale locale, TimeZone timeZone) {
	LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(this.request);
	if (!(localeResolver instanceof LocaleContextResolver)) {
		throw new IllegalStateException("Cannot change locale context if no LocaleContextResolver configured");
	}
	((LocaleContextResolver) localeResolver).setLocaleContext(this.request, this.response,
			new SimpleTimeZoneAwareLocaleContext(locale, timeZone));
	this.locale = locale;
	this.timeZone = timeZone;
}
 

/**
 * Change the current locale to the specified locale and time zone context,
 * storing the new locale context through the configured {@link LocaleResolver}.
 * @param locale the new locale
 * @param timeZone the new time zone
 * @see LocaleContextResolver#setLocaleContext
 * @see org.springframework.context.i18n.SimpleTimeZoneAwareLocaleContext
 */
public void changeLocale(Locale locale, TimeZone timeZone) {
	LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(this.request);
	if (!(localeResolver instanceof LocaleContextResolver)) {
		throw new IllegalStateException("Cannot change locale context if no LocaleContextResolver configured");
	}
	((LocaleContextResolver) localeResolver).setLocaleContext(this.request, this.response,
			new SimpleTimeZoneAwareLocaleContext(locale, timeZone));
	this.locale = locale;
	this.timeZone = timeZone;
}
 

/**
 * Change the current locale to the specified locale and time zone context,
 * storing the new locale context through the configured {@link LocaleResolver}.
 * @param locale the new locale
 * @param timeZone the new time zone
 * @see LocaleContextResolver#setLocaleContext
 * @see org.springframework.context.i18n.SimpleTimeZoneAwareLocaleContext
 */
public void changeLocale(Locale locale, TimeZone timeZone) {
	LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(this.request);
	if (!(localeResolver instanceof LocaleContextResolver)) {
		throw new IllegalStateException("Cannot change locale context if no LocaleContextResolver configured");
	}
	((LocaleContextResolver) localeResolver).setLocaleContext(this.request, this.response,
			new SimpleTimeZoneAwareLocaleContext(locale, timeZone));
	this.locale = locale;
	this.timeZone = timeZone;
}
 

/**
 * Create a new RequestContext for the given request, using the given model attributes for Errors retrieval.
 * <p>This works with all View implementations. It will typically be used by View implementations.
 * <p>If a ServletContext is specified, the RequestContext will also work with a root
 * WebApplicationContext (outside a DispatcherServlet).
 * @param request current HTTP request
 * @param response current HTTP response
 * @param servletContext the servlet context of the web application (can be {@code null}; necessary for
 * fallback to root WebApplicationContext)
 * @param model the model attributes for the current view (can be {@code null}, using the request attributes
 * for Errors retrieval)
 * @see org.springframework.web.context.WebApplicationContext
 * @see org.springframework.web.servlet.DispatcherServlet
 */
public RequestContext(HttpServletRequest request, @Nullable HttpServletResponse response,
		@Nullable ServletContext servletContext, @Nullable Map<String, Object> model) {

	this.request = request;
	this.response = response;
	this.model = model;

	// Fetch WebApplicationContext, either from DispatcherServlet or the root context.
	// ServletContext needs to be specified to be able to fall back to the root context!
	WebApplicationContext wac = (WebApplicationContext) request.getAttribute(WEB_APPLICATION_CONTEXT_ATTRIBUTE);
	if (wac == null) {
		wac = RequestContextUtils.findWebApplicationContext(request, servletContext);
		if (wac == null) {
			throw new IllegalStateException("No WebApplicationContext found: not in a DispatcherServlet " +
					"request and no ContextLoaderListener registered?");
		}
	}
	this.webApplicationContext = wac;

	Locale locale = null;
	TimeZone timeZone = null;

	// Determine locale to use for this RequestContext.
	LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(request);
	if (localeResolver instanceof LocaleContextResolver) {
		LocaleContext localeContext = ((LocaleContextResolver) localeResolver).resolveLocaleContext(request);
		locale = localeContext.getLocale();
		if (localeContext instanceof TimeZoneAwareLocaleContext) {
			timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
		}
	}
	else if (localeResolver != null) {
		// Try LocaleResolver (we're within a DispatcherServlet request).
		locale = localeResolver.resolveLocale(request);
	}

	this.locale = locale;
	this.timeZone = timeZone;

	// Determine default HTML escape setting from the "defaultHtmlEscape"
	// context-param in web.xml, if any.
	this.defaultHtmlEscape = WebUtils.getDefaultHtmlEscape(this.webApplicationContext.getServletContext());

	// Determine response-encoded HTML escape setting from the "responseEncodedHtmlEscape"
	// context-param in web.xml, if any.
	this.responseEncodedHtmlEscape =
			WebUtils.getResponseEncodedHtmlEscape(this.webApplicationContext.getServletContext());

	this.urlPathHelper = new UrlPathHelper();

	if (this.webApplicationContext.containsBean(RequestContextUtils.REQUEST_DATA_VALUE_PROCESSOR_BEAN_NAME)) {
		this.requestDataValueProcessor = this.webApplicationContext.getBean(
				RequestContextUtils.REQUEST_DATA_VALUE_PROCESSOR_BEAN_NAME, RequestDataValueProcessor.class);
	}
}
 

/**
 * Create a new RequestContext for the given request, using the given model attributes for Errors retrieval.
 * <p>This works with all View implementations. It will typically be used by View implementations.
 * <p>If a ServletContext is specified, the RequestContext will also work with a root
 * WebApplicationContext (outside a DispatcherServlet).
 * @param request current HTTP request
 * @param response current HTTP response
 * @param servletContext the servlet context of the web application (can be {@code null}; necessary for
 * fallback to root WebApplicationContext)
 * @param model the model attributes for the current view (can be {@code null}, using the request attributes
 * for Errors retrieval)
 * @see org.springframework.web.context.WebApplicationContext
 * @see org.springframework.web.servlet.DispatcherServlet
 */
public RequestContext(HttpServletRequest request, @Nullable HttpServletResponse response,
		@Nullable ServletContext servletContext, @Nullable Map<String, Object> model) {

	this.request = request;
	this.response = response;
	this.model = model;

	// Fetch WebApplicationContext, either from DispatcherServlet or the root context.
	// ServletContext needs to be specified to be able to fall back to the root context!
	WebApplicationContext wac = (WebApplicationContext) request.getAttribute(WEB_APPLICATION_CONTEXT_ATTRIBUTE);
	if (wac == null) {
		wac = RequestContextUtils.findWebApplicationContext(request, servletContext);
		if (wac == null) {
			throw new IllegalStateException("No WebApplicationContext found: not in a DispatcherServlet " +
					"request and no ContextLoaderListener registered?");
		}
	}
	this.webApplicationContext = wac;

	Locale locale = null;
	TimeZone timeZone = null;

	// Determine locale to use for this RequestContext.
	LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(request);
	if (localeResolver instanceof LocaleContextResolver) {
		LocaleContext localeContext = ((LocaleContextResolver) localeResolver).resolveLocaleContext(request);
		locale = localeContext.getLocale();
		if (localeContext instanceof TimeZoneAwareLocaleContext) {
			timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
		}
	}
	else if (localeResolver != null) {
		// Try LocaleResolver (we're within a DispatcherServlet request).
		locale = localeResolver.resolveLocale(request);
	}

	this.locale = locale;
	this.timeZone = timeZone;

	// Determine default HTML escape setting from the "defaultHtmlEscape"
	// context-param in web.xml, if any.
	this.defaultHtmlEscape = WebUtils.getDefaultHtmlEscape(this.webApplicationContext.getServletContext());

	// Determine response-encoded HTML escape setting from the "responseEncodedHtmlEscape"
	// context-param in web.xml, if any.
	this.responseEncodedHtmlEscape =
			WebUtils.getResponseEncodedHtmlEscape(this.webApplicationContext.getServletContext());

	this.urlPathHelper = new UrlPathHelper();

	if (this.webApplicationContext.containsBean(RequestContextUtils.REQUEST_DATA_VALUE_PROCESSOR_BEAN_NAME)) {
		this.requestDataValueProcessor = this.webApplicationContext.getBean(
				RequestContextUtils.REQUEST_DATA_VALUE_PROCESSOR_BEAN_NAME, RequestDataValueProcessor.class);
	}
}
 

/**
 * Initialize this context with the given request, using the given model attributes for Errors retrieval.
 * <p>Delegates to {@code getFallbackLocale} and {@code getFallbackTheme} for determining the fallback
 * locale and theme, respectively, if no LocaleResolver and/or ThemeResolver can be found in the request.
 * @param request current HTTP request
 * @param servletContext the servlet context of the web application (can be {@code null}; necessary for
 * fallback to root WebApplicationContext)
 * @param model the model attributes for the current view (can be {@code null}, using the request attributes
 * for Errors retrieval)
 * @see #getFallbackLocale
 * @see #getFallbackTheme
 * @see org.springframework.web.servlet.DispatcherServlet#LOCALE_RESOLVER_ATTRIBUTE
 * @see org.springframework.web.servlet.DispatcherServlet#THEME_RESOLVER_ATTRIBUTE
 */
protected void initContext(HttpServletRequest request, HttpServletResponse response, ServletContext servletContext,
		Map<String, Object> model) {

	this.request = request;
	this.response = response;
	this.model = model;

	// Fetch WebApplicationContext, either from DispatcherServlet or the root context.
	// ServletContext needs to be specified to be able to fall back to the root context!
	this.webApplicationContext = (WebApplicationContext) request.getAttribute(WEB_APPLICATION_CONTEXT_ATTRIBUTE);
	if (this.webApplicationContext == null) {
		this.webApplicationContext = RequestContextUtils.findWebApplicationContext(request, servletContext);
		if (this.webApplicationContext == null) {
			throw new IllegalStateException("No WebApplicationContext found: not in a DispatcherServlet " +
					"request and no ContextLoaderListener registered?");
		}
	}

	// Determine locale to use for this RequestContext.
	LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(request);
	if (localeResolver instanceof LocaleContextResolver) {
		LocaleContext localeContext = ((LocaleContextResolver) localeResolver).resolveLocaleContext(request);
		this.locale = localeContext.getLocale();
		if (localeContext instanceof TimeZoneAwareLocaleContext) {
			this.timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
		}
	}
	else if (localeResolver != null) {
		// Try LocaleResolver (we're within a DispatcherServlet request).
		this.locale = localeResolver.resolveLocale(request);
	}

	// Try JSTL fallbacks if necessary.
	if (this.locale == null) {
		this.locale = getFallbackLocale();
	}
	if (this.timeZone == null) {
		this.timeZone = getFallbackTimeZone();
	}

	// Determine default HTML escape setting from the "defaultHtmlEscape"
	// context-param in web.xml, if any.
	this.defaultHtmlEscape = WebUtils.getDefaultHtmlEscape(this.webApplicationContext.getServletContext());

	// Determine response-encoded HTML escape setting from the "responseEncodedHtmlEscape"
	// context-param in web.xml, if any.
	this.responseEncodedHtmlEscape = WebUtils.getResponseEncodedHtmlEscape(this.webApplicationContext.getServletContext());

	this.urlPathHelper = new UrlPathHelper();

	if (this.webApplicationContext.containsBean(RequestContextUtils.REQUEST_DATA_VALUE_PROCESSOR_BEAN_NAME)) {
		this.requestDataValueProcessor = this.webApplicationContext.getBean(
				RequestContextUtils.REQUEST_DATA_VALUE_PROCESSOR_BEAN_NAME, RequestDataValueProcessor.class);
	}
}
 

/**
 * Initialize this context with the given request, using the given model attributes for Errors retrieval.
 * <p>Delegates to {@code getFallbackLocale} and {@code getFallbackTheme} for determining the fallback
 * locale and theme, respectively, if no LocaleResolver and/or ThemeResolver can be found in the request.
 * @param request current HTTP request
 * @param servletContext the servlet context of the web application (can be {@code null}; necessary for
 * fallback to root WebApplicationContext)
 * @param model the model attributes for the current view (can be {@code null}, using the request attributes
 * for Errors retrieval)
 * @see #getFallbackLocale
 * @see #getFallbackTheme
 * @see org.springframework.web.servlet.DispatcherServlet#LOCALE_RESOLVER_ATTRIBUTE
 * @see org.springframework.web.servlet.DispatcherServlet#THEME_RESOLVER_ATTRIBUTE
 */
protected void initContext(HttpServletRequest request, HttpServletResponse response, ServletContext servletContext,
		Map<String, Object> model) {

	this.request = request;
	this.response = response;
	this.model = model;

	// Fetch WebApplicationContext, either from DispatcherServlet or the root context.
	// ServletContext needs to be specified to be able to fall back to the root context!
	this.webApplicationContext = (WebApplicationContext) request.getAttribute(WEB_APPLICATION_CONTEXT_ATTRIBUTE);
	if (this.webApplicationContext == null) {
		this.webApplicationContext = RequestContextUtils.findWebApplicationContext(request, servletContext);
		if (this.webApplicationContext == null) {
			throw new IllegalStateException("No WebApplicationContext found: not in a DispatcherServlet " +
					"request and no ContextLoaderListener registered?");
		}
	}

	// Determine locale to use for this RequestContext.
	LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(request);
	if (localeResolver instanceof LocaleContextResolver) {
		LocaleContext localeContext = ((LocaleContextResolver) localeResolver).resolveLocaleContext(request);
		this.locale = localeContext.getLocale();
		if (localeContext instanceof TimeZoneAwareLocaleContext) {
			this.timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
		}
	}
	else if (localeResolver != null) {
		// Try LocaleResolver (we're within a DispatcherServlet request).
		this.locale = localeResolver.resolveLocale(request);
	}

	// Try JSTL fallbacks if necessary.
	if (this.locale == null) {
		this.locale = getFallbackLocale();
	}
	if (this.timeZone == null) {
		this.timeZone = getFallbackTimeZone();
	}

	// Determine default HTML escape setting from the "defaultHtmlEscape"
	// context-param in web.xml, if any.
	this.defaultHtmlEscape = WebUtils.getDefaultHtmlEscape(this.webApplicationContext.getServletContext());

	// Determine response-encoded HTML escape setting from the "responseEncodedHtmlEscape"
	// context-param in web.xml, if any.
	this.responseEncodedHtmlEscape = WebUtils.getResponseEncodedHtmlEscape(this.webApplicationContext.getServletContext());

	this.urlPathHelper = new UrlPathHelper();

	if (this.webApplicationContext.containsBean(RequestContextUtils.REQUEST_DATA_VALUE_PROCESSOR_BEAN_NAME)) {
		this.requestDataValueProcessor = this.webApplicationContext.getBean(
				RequestContextUtils.REQUEST_DATA_VALUE_PROCESSOR_BEAN_NAME, RequestDataValueProcessor.class);
	}
}
 

/**
 * Retrieve the current time zone from the given request, using the
 * TimeZoneAwareLocaleResolver bound to the request by the DispatcherServlet
 * (if available), falling back to the system's default time zone.
 * <p>Note: This method returns {@code null} if no specific time zone can be
 * resolved for the given request. This is in contrast to {@link #getLocale}
 * where there is always the request's accept-header locale to fall back to.
 * <p>Consider using {@link org.springframework.context.i18n.LocaleContextHolder#getTimeZone()}
 * which will normally be populated with the same TimeZone: That method only
 * differs in terms of its fallback to the system time zone if the LocaleResolver
 * hasn't provided a specific time zone (instead of this method's {@code null}).
 * @param request current HTTP request
 * @return the current time zone for the given request, either from the
 * TimeZoneAwareLocaleResolver or {@code null} if none associated
 * @see #getLocaleResolver
 * @see org.springframework.context.i18n.LocaleContextHolder#getTimeZone()
 */
@Nullable
public static TimeZone getTimeZone(HttpServletRequest request) {
	LocaleResolver localeResolver = getLocaleResolver(request);
	if (localeResolver instanceof LocaleContextResolver) {
		LocaleContext localeContext = ((LocaleContextResolver) localeResolver).resolveLocaleContext(request);
		if (localeContext instanceof TimeZoneAwareLocaleContext) {
			return ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
		}
	}
	return null;
}
 

/**
 * Retrieve the current time zone from the given request, using the
 * TimeZoneAwareLocaleResolver bound to the request by the DispatcherServlet
 * (if available), falling back to the system's default time zone.
 * <p>Note: This method returns {@code null} if no specific time zone can be
 * resolved for the given request. This is in contrast to {@link #getLocale}
 * where there is always the request's accept-header locale to fall back to.
 * <p>Consider using {@link org.springframework.context.i18n.LocaleContextHolder#getTimeZone()}
 * which will normally be populated with the same TimeZone: That method only
 * differs in terms of its fallback to the system time zone if the LocaleResolver
 * hasn't provided a specific time zone (instead of this method's {@code null}).
 * @param request current HTTP request
 * @return the current time zone for the given request, either from the
 * TimeZoneAwareLocaleResolver or {@code null} if none associated
 * @see #getLocaleResolver
 * @see org.springframework.context.i18n.LocaleContextHolder#getTimeZone()
 */
@Nullable
public static TimeZone getTimeZone(HttpServletRequest request) {
	LocaleResolver localeResolver = getLocaleResolver(request);
	if (localeResolver instanceof LocaleContextResolver) {
		LocaleContext localeContext = ((LocaleContextResolver) localeResolver).resolveLocaleContext(request);
		if (localeContext instanceof TimeZoneAwareLocaleContext) {
			return ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
		}
	}
	return null;
}
 

/**
 * Retrieve the current time zone from the given request, using the
 * TimeZoneAwareLocaleResolver bound to the request by the DispatcherServlet
 * (if available), falling back to the system's default time zone.
 * <p>Note: This method returns {@code null} if no specific time zone can be
 * resolved for the given request. This is in contrast to {@link #getLocale}
 * where there is always the request's accept-header locale to fall back to.
 * <p>Consider using {@link org.springframework.context.i18n.LocaleContextHolder#getTimeZone()}
 * which will normally be populated with the same TimeZone: That method only
 * differs in terms of its fallback to the system time zone if the LocaleResolver
 * hasn't provided a specific time zone (instead of this method's {@code null}).
 * @param request current HTTP request
 * @return the current time zone for the given request, either from the
 * TimeZoneAwareLocaleResolver or {@code null} if none associated
 * @see #getLocaleResolver
 * @see org.springframework.context.i18n.LocaleContextHolder#getTimeZone()
 */
public static TimeZone getTimeZone(HttpServletRequest request) {
	LocaleResolver localeResolver = getLocaleResolver(request);
	if (localeResolver instanceof LocaleContextResolver) {
		LocaleContext localeContext = ((LocaleContextResolver) localeResolver).resolveLocaleContext(request);
		if (localeContext instanceof TimeZoneAwareLocaleContext) {
			return ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
		}
	}
	return null;
}
 

/**
 * Retrieve the current time zone from the given request, using the
 * TimeZoneAwareLocaleResolver bound to the request by the DispatcherServlet
 * (if available), falling back to the system's default time zone.
 * <p>Note: This method returns {@code null} if no specific time zone can be
 * resolved for the given request. This is in contrast to {@link #getLocale}
 * where there is always the request's accept-header locale to fall back to.
 * <p>Consider using {@link org.springframework.context.i18n.LocaleContextHolder#getTimeZone()}
 * which will normally be populated with the same TimeZone: That method only
 * differs in terms of its fallback to the system time zone if the LocaleResolver
 * hasn't provided provided a specific time zone (instead of this method's {@code null}).
 * @param request current HTTP request
 * @return the current time zone for the given request, either from the
 * TimeZoneAwareLocaleResolver or {@code null} if none associated
 * @see #getLocaleResolver
 * @see org.springframework.context.i18n.LocaleContextHolder#getTimeZone()
 */
public static TimeZone getTimeZone(HttpServletRequest request) {
	LocaleResolver localeResolver = getLocaleResolver(request);
	if (localeResolver instanceof LocaleContextResolver) {
		LocaleContext localeContext = ((LocaleContextResolver) localeResolver).resolveLocaleContext(request);
		if (localeContext instanceof TimeZoneAwareLocaleContext) {
			return ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
		}
	}
	return null;
}