Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.apache.wicket.util.cookies; import javax.servlet.http.Cookie; import org.apache.wicket.markup.html.form.FormComponent; import org.apache.wicket.protocol.http.WebApplication; import org.apache.wicket.protocol.http.servlet.ServletWebRequest; import org.apache.wicket.request.Response; import org.apache.wicket.request.cycle.RequestCycle; import org.apache.wicket.request.http.WebRequest; import org.apache.wicket.request.http.WebResponse; import org.apache.wicket.util.string.Strings; import org.apache.wicket.util.time.Time; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Helper class to simplify Cookie handling. * * @author Juergen Donnerstag * @author Jonathan Locke */ public class CookieUtils { private final static Logger log = LoggerFactory.getLogger(CookieUtils.class); public static final String DEFAULT_SESSIONID_COOKIE_NAME = "JSESSIONID"; private final CookieDefaults settings; /** * Construct. */ public CookieUtils() { settings = new CookieDefaults(); } /** * Construct. * * @param settings * the default settings for the saved cookies */ public CookieUtils(final CookieDefaults settings) { this.settings = settings; } /** * @return Gets the settings for these utils */ public final CookieDefaults getSettings() { return settings; } /** * Remove the cookie identified by the key * * @param key * The cookie name */ public final void remove(final String key) { final Cookie cookie = getCookie(key); if (cookie != null) { remove(cookie); } } /** * Remove the cookie identified by the form component * * @param formComponent */ public final void remove(final FormComponent<?> formComponent) { remove(getKey(formComponent)); } /** * This method gets used when a cookie key needs to be derived from a form component. By default * the component's page relative path is used. * * @param component * @return cookie key */ protected String getKey(final FormComponent<?> component) { return component.getPageRelativePath(); } /** * Retrieve the cookie value by means of its key. * * @param key * The cookie name * @return The cookie value associated with the key */ public final String load(final String key) { final Cookie cookie = getCookie(key); if (cookie != null) { return cookie.getValue(); } return null; } /** * Retrieve the cookie value associated with the formComponent and load the model object with * the cookie value. * * @param formComponent * @return The Cookie value which has also been used to set the component's model value */ public final String load(final FormComponent<?> formComponent) { String value = load(getKey(formComponent)); if (value != null) { // Assign the retrieved/persisted value to the component formComponent.setModelValue(new String[] { value }); } return value; } /** * Create a Cookie with key and value and save it in the browser with the next response * * @param key * The cookie name * @param value * The cookie value */ public final void save(String key, final String value) { key = getSaveKey(key); Cookie cookie = getCookie(key); if (cookie == null) { cookie = new Cookie(key, value); } else { cookie.setValue(value); } save(cookie); } /** * Save the form components model value in a cookie * * @param formComponent */ public final void save(final FormComponent<?> formComponent) { save(getKey(formComponent), formComponent.getValue()); } /** * Make sure the 'key' does not contain any illegal chars. E.g. for cookies ':' is not allowed. * * @param key * The key to be validated * @return The save key */ protected String getSaveKey(String key) { if (Strings.isEmpty(key)) { throw new IllegalArgumentException("A Cookie name can not be null or empty"); } // cookie names cannot contain ':', // we replace ':' with '.' but first we have to encode '.' as '..' key = Strings.replaceAll(key, ".", "..").toString(); key = key.replace(':', '.'); return key; } /** * Convenience method for deleting a cookie by name. Delete the cookie by setting its maximum * age to zero. * * @param cookie * The cookie to delete */ private void remove(final Cookie cookie) { if (cookie != null) { save(cookie); // Delete the cookie by setting its maximum age to zero cookie.setMaxAge(0); cookie.setValue(null); if (log.isDebugEnabled()) { log.debug("Removed Cookie: " + cookie.getName()); } } } /** * Gets the cookie with 'name' attached to the latest WebRequest. * * @param name * The name of the cookie to be looked up * * @return Any cookies for this request */ public Cookie getCookie(final String name) { String key = getSaveKey(name); try { WebRequest webRequest = getWebRequest(); Cookie cookie = webRequest.getCookie(key); if (log.isDebugEnabled()) { if (cookie != null) { log.debug( "Found Cookie with name=" + key + " and request URI=" + webRequest.getUrl().toString()); } else { log.debug("Unable to find Cookie with name=" + key + " and request URI=" + webRequest.getUrl().toString()); } } return cookie; } catch (NullPointerException ex) { // Ignore any app server problem here } return null; } /** * Gets the name of the cookie where the session id is stored. * * @param application * The current we application holding the {@link javax.servlet.ServletContext}. * * @return The name set in {@link javax.servlet.SessionCookieConfig} or the default value 'JSESSIONID' if not set */ public String getSessionIdCookieName(WebApplication application) { String jsessionCookieName = application.getServletContext().getSessionCookieConfig().getName(); return jsessionCookieName == null ? DEFAULT_SESSIONID_COOKIE_NAME : jsessionCookieName; } /** * Persist/save the data using Cookies. * * @param cookie * The Cookie to be persisted. * @return The cookie provided */ private Cookie save(final Cookie cookie) { if (cookie == null) { return null; } initializeCookie(cookie); getWebResponse().addCookie(cookie); if (log.isDebugEnabled()) { log.debug("Cookie saved: " + cookieToDebugString(cookie) + "; request URI=" + getWebRequest().getUrl().toString()); } return cookie; } /** * Is called before the Cookie is saved. May be subclassed for different (dynamic) Cookie * parameters. Static parameters can also be changed via {@link CookieDefaults}. * * @param cookie */ protected void initializeCookie(final Cookie cookie) { final String comment = settings.getComment(); if (comment != null) { cookie.setComment(comment); } final String domain = settings.getDomain(); if (domain != null) { cookie.setDomain(domain); } ServletWebRequest request = (ServletWebRequest) getWebRequest(); String path = request.getContainerRequest().getContextPath() + "/" + request.getFilterPrefix(); cookie.setPath(path); cookie.setVersion(settings.getVersion()); cookie.setSecure(settings.getSecure()); cookie.setMaxAge(settings.getMaxAge()); cookie.setHttpOnly(settings.isHttpOnly()); } /** * Convenience method to get the http request. * * @return WebRequest related to the RequestCycle */ private WebRequest getWebRequest() { return (WebRequest) RequestCycle.get().getRequest(); } /** * Convenience method to get the http response. * * @return WebResponse related to the RequestCycle */ private WebResponse getWebResponse() { RequestCycle cycle = RequestCycle.get(); Response response = cycle.getResponse(); if (!(response instanceof WebResponse)) { response = cycle.getOriginalResponse(); } return (WebResponse) response; } /** * Gets debug info as a string for the given cookie. * * @param cookie * the cookie to debug. * @return a string that represents the internals of the cookie. */ private String cookieToDebugString(final Cookie cookie) { return "[Cookie " + " name = " + cookie.getName() + ", value = " + cookie.getValue() + ", domain = " + cookie.getDomain() + ", path = " + cookie.getPath() + ", maxAge = " + Time.millis(cookie.getMaxAge()).toDateString() + "(" + cookie.getMaxAge() + ")" + "]"; } }