org.springframework.web.servlet.theme.SessionThemeResolver Maven / Gradle / Ivy
/*
* 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
* limitations under the License.
*/
package org.springframework.web.servlet.theme;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.lang.Nullable;
import org.springframework.util.StringUtils;
import org.springframework.web.util.WebUtils;
/**
* {@link org.springframework.web.servlet.ThemeResolver} implementation that
* uses a theme attribute in the user's session in case of a custom setting,
* with a fallback to the default theme. This is most appropriate if the
* application needs user sessions anyway.
*
* Custom controllers can override the user's theme by calling
* {@code setThemeName}, e.g. responding to a theme change request.
*
* @author Jean-Pierre Pawlak
* @author Juergen Hoeller
* @since 17.06.2003
* @see #setThemeName
*/
public class SessionThemeResolver extends AbstractThemeResolver {
/**
* Name of the session attribute that holds the theme name.
* Only used internally by this implementation.
* Use {@code RequestContext(Utils).getTheme()}
* to retrieve the current theme in controllers or views.
* @see org.springframework.web.servlet.support.RequestContext#getTheme
* @see org.springframework.web.servlet.support.RequestContextUtils#getTheme
*/
public static final String THEME_SESSION_ATTRIBUTE_NAME = SessionThemeResolver.class.getName() + ".THEME";
@Override
public String resolveThemeName(HttpServletRequest request) {
String themeName = (String) WebUtils.getSessionAttribute(request, THEME_SESSION_ATTRIBUTE_NAME);
// A specific theme indicated, or do we need to fallback to the default?
return (themeName != null ? themeName : getDefaultThemeName());
}
@Override
public void setThemeName(
HttpServletRequest request, @Nullable HttpServletResponse response, @Nullable String themeName) {
WebUtils.setSessionAttribute(request, THEME_SESSION_ATTRIBUTE_NAME,
(StringUtils.hasText(themeName) ? themeName : null));
}
}