001/* 002 * Copyright 2002-2013 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; 018 019import javax.servlet.http.HttpServletRequest; 020import javax.servlet.http.HttpServletResponse; 021 022/** 023 * Interface for web-based theme resolution strategies that allows for 024 * both theme resolution via the request and theme modification via 025 * request and response. 026 * 027 * <p>This interface allows for implementations based on session, 028 * cookies, etc. The default implementation is 029 * {@link org.springframework.web.servlet.theme.FixedThemeResolver}, 030 * simply using a configured default theme. 031 * 032 * <p>Note that this resolver is only responsible for determining the 033 * current theme name. The Theme instance for the resolved theme name 034 * gets looked up by DispatcherServlet via the respective ThemeSource, 035 * i.e. the current WebApplicationContext. 036 * 037 * <p>Use {@link org.springframework.web.servlet.support.RequestContext#getTheme()} 038 * to retrieve the current theme in controllers or views, independent 039 * of the actual resolution strategy. 040 * 041 * @author Jean-Pierre Pawlak 042 * @author Juergen Hoeller 043 * @since 17.06.2003 044 * @see org.springframework.ui.context.Theme 045 * @see org.springframework.ui.context.ThemeSource 046 */ 047public interface ThemeResolver { 048 049 /** 050 * Resolve the current theme name via the given request. 051 * Should return a default theme as fallback in any case. 052 * @param request request to be used for resolution 053 * @return the current theme name 054 */ 055 String resolveThemeName(HttpServletRequest request); 056 057 /** 058 * Set the current theme name to the given one. 059 * @param request request to be used for theme name modification 060 * @param response response to be used for theme name modification 061 * @param themeName the new theme name 062 * @throws UnsupportedOperationException if the ThemeResolver implementation 063 * does not support dynamic changing of the theme 064 */ 065 void setThemeName(HttpServletRequest request, HttpServletResponse response, String themeName); 066 067}