Spring Framework example source code file (CookieThemeResolver.java)

This example Spring Framework source code file (CookieThemeResolver.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

cookie, cookiegenerator, cookiethemeresolver, cookiethemeresolver, default_cookie_name, http, httpservletresponse, original_default_theme_name, original_default_theme_name, request, response, servlet, string, string, theme, theme, theme_request_attribute_name, themeresolver

The Spring Framework CookieThemeResolver.java source code

/*
 * Copyright 2002-2005 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.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ThemeResolver;
import org.springframework.web.util.CookieGenerator;
import org.springframework.web.util.WebUtils;

/**
 * Implementation of ThemeResolver that uses a cookie sent back to the user
 * in case of a custom setting, with a fallback to the default theme.
 * This is particularly useful for stateless applications without user sessions.
 *
 * <p>Custom controllers can thus override the user's theme by calling
 * <code>setThemeName, e.g. responding to a certain theme change request.
 *
 * @author Jean-Pierre Pawlak
 * @author Juergen Hoeller
 * @since 17.06.2003
 * @see #setThemeName
 */
public class CookieThemeResolver extends CookieGenerator implements ThemeResolver {

	public final static String ORIGINAL_DEFAULT_THEME_NAME = "theme";

	/**
	 * Name of the request attribute that holds the theme name. Only used
	 * for overriding a cookie value if the theme has been changed in the
	 * course of the current request! Use RequestContext.getTheme() to
	 * retrieve the current theme in controllers or views.
	 * @see org.springframework.web.servlet.support.RequestContext#getTheme
	 */
	public static final String THEME_REQUEST_ATTRIBUTE_NAME = CookieThemeResolver.class.getName() + ".THEME";

	public static final String DEFAULT_COOKIE_NAME = CookieThemeResolver.class.getName() + ".THEME";


	private String defaultThemeName = ORIGINAL_DEFAULT_THEME_NAME;


	public CookieThemeResolver() {
		setCookieName(DEFAULT_COOKIE_NAME);
	}


	/**
	 * Set the name of the default theme.
	 */
	public void setDefaultThemeName(String defaultThemeName) {
		this.defaultThemeName = defaultThemeName;
	}

	/**
	 * Return the name of the default theme.
	 */
	public String getDefaultThemeName() {
		return defaultThemeName;
	}


	public String resolveThemeName(HttpServletRequest request) {
		// Check request for preparsed or preset theme.
		String theme = (String) request.getAttribute(THEME_REQUEST_ATTRIBUTE_NAME);
		if (theme != null) {
			return theme;
		}

		// Retrieve cookie value from request.
		Cookie cookie = WebUtils.getCookie(request, getCookieName());
		if (cookie != null) {
			return cookie.getValue();
		}

		// Fall back to default theme.
		return getDefaultThemeName();
	}

	public void setThemeName(HttpServletRequest request, HttpServletResponse response, String themeName) {
		if (themeName != null) {
			// Set request attribute and add cookie.
			request.setAttribute(THEME_REQUEST_ATTRIBUTE_NAME, themeName);
			addCookie(response, themeName);
		}

		else {
			// Set request attribute to fallback theme and remove cookie.
			request.setAttribute(THEME_REQUEST_ATTRIBUTE_NAME, getDefaultThemeName());
			removeCookie(response);
		}
	}

}