Java tutorial
/* * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.net; import java.util.Map; import java.util.List; import java.io.IOException; import sun.security.util.SecurityConstants; /** * A CookieHandler object provides a callback mechanism to hook up a * HTTP state management policy implementation into the HTTP protocol * handler. The HTTP state management mechanism specifies a way to * create a stateful session with HTTP requests and responses. * * <p> A system-wide CookieHandler to be used by the {@linkplain * HttpURLConnection HTTP URL stream protocol handler} can be registered by * doing a CookieHandler.setDefault(CookieHandler). The currently registered * CookieHandler can be retrieved by calling * CookieHandler.getDefault(). * * For more information on HTTP state management, see <a * href="http://www.ietf.org/rfc/rfc2965.txt"><i>RFC 2965: HTTP * State Management Mechanism</i></a> * * @author Yingxian Wang * @since 1.5 */ public abstract class CookieHandler { /** * The system-wide cookie handler that will apply cookies to the * request headers and manage cookies from the response headers. * * @see setDefault(CookieHandler) * @see getDefault() */ private static CookieHandler cookieHandler; /** * Gets the system-wide cookie handler. * * @return the system-wide cookie handler; A null return means * there is no system-wide cookie handler currently set. * @throws SecurityException * If a security manager has been installed and it denies * {@link NetPermission}{@code ("getCookieHandler")} * @see #setDefault(CookieHandler) */ public static synchronized CookieHandler getDefault() { SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(SecurityConstants.GET_COOKIEHANDLER_PERMISSION); } return cookieHandler; } /** * Sets (or unsets) the system-wide cookie handler. * * Note: non-standard http protocol handlers may ignore this setting. * * @param cHandler The HTTP cookie handler, or * {@code null} to unset. * @throws SecurityException * If a security manager has been installed and it denies * {@link NetPermission}{@code ("setCookieHandler")} * @see #getDefault() */ public static synchronized void setDefault(CookieHandler cHandler) { SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(SecurityConstants.SET_COOKIEHANDLER_PERMISSION); } cookieHandler = cHandler; } /** * Gets all the applicable cookies from a cookie cache for the * specified uri in the request header. * * <P>The {@code URI} passed as an argument specifies the intended use for * the cookies. In particular the scheme should reflect whether the cookies * will be sent over http, https or used in another context like javascript. * The host part should reflect either the destination of the cookies or * their origin in the case of javascript.</P> * <P>It is up to the implementation to take into account the {@code URI} and * the cookies attributes and security settings to determine which ones * should be returned.</P> * * <P>HTTP protocol implementers should make sure that this method is * called after all request headers related to choosing cookies * are added, and before the request is sent.</P> * * @param uri a {@code URI} representing the intended use for the * cookies * @param requestHeaders - a Map from request header * field names to lists of field values representing * the current request headers * @return an immutable map from state management headers, with * field names "Cookie" or "Cookie2" to a list of * cookies containing state information * * @throws IOException if an I/O error occurs * @throws IllegalArgumentException if either argument is null * @see #put(URI, Map) */ public abstract Map<String, List<String>> get(URI uri, Map<String, List<String>> requestHeaders) throws IOException; /** * Sets all the applicable cookies, examples are response header * fields that are named Set-Cookie2, present in the response * headers into a cookie cache. * * @param uri a {@code URI} where the cookies come from * @param responseHeaders an immutable map from field names to * lists of field values representing the response * header fields returned * @throws IOException if an I/O error occurs * @throws IllegalArgumentException if either argument is null * @see #get(URI, Map) */ public abstract void put(URI uri, Map<String, List<String>> responseHeaders) throws IOException; }