/*
* Copyright 2002-2008 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
*
* http://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.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ThemeResolver;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import org.springframework.web.servlet.support.RequestContextUtils;
/**
* Interceptor that allows for changing the current theme on every request,
* via a configurable request parameter.
*
* @author Juergen Hoeller
* @since 20.06.2003
* @see org.springframework.web.servlet.ThemeResolver
*/
public class ThemeChangeInterceptor extends HandlerInterceptorAdapter {
/**
* Default name of the theme specification parameter: "theme".
*/
public static final String DEFAULT_PARAM_NAME = "theme";
private String paramName = DEFAULT_PARAM_NAME;
/**
* Set the name of the parameter that contains a theme specification
* in a theme change request. Default is "theme".
*/
public void setParamName(String paramName) {
this.paramName = paramName;
}
/**
* Return the name of the parameter that contains a theme specification
* in a theme change request.
*/
public String getParamName() {
return this.paramName;
}
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws ServletException {
ThemeResolver themeResolver = RequestContextUtils.getThemeResolver(request);
if (themeResolver == null) {
throw new IllegalStateException("No ThemeResolver found: not in a DispatcherServlet request?");
}
String newTheme = request.getParameter(this.paramName);
if (newTheme != null) {
themeResolver.setThemeName(request, response, newTheme);
}
// Proceed in any case.
return true;
}
}