author | weijun |
Tue, 26 Jun 2018 18:55:48 +0800 | |
changeset 50788 | 6274aee1f692 |
parent 47216 | 71c04702a3d5 |
child 52499 | 768b1c612100 |
permissions | -rw-r--r-- |
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/* |
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* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package java.net; |
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import java.io.IOException; |
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import java.util.Map; |
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import java.util.List; |
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import sun.security.util.SecurityConstants; |
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/** |
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* Represents implementations of URLConnection caches. An instance of |
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* such a class can be registered with the system by doing |
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* ResponseCache.setDefault(ResponseCache), and the system will call |
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* this object in order to: |
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* |
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* <ul><li>store resource data which has been retrieved from an |
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* external source into the cache</li> |
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* <li>try to fetch a requested resource that may have been |
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* stored in the cache</li> |
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* </ul> |
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* |
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* The ResponseCache implementation decides which resources |
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* should be cached, and for how long they should be cached. If a |
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* request resource cannot be retrieved from the cache, then the |
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* protocol handlers will fetch the resource from its original |
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* location. |
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* |
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* The settings for URLConnection#useCaches controls whether the |
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* protocol is allowed to use a cached response. |
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* |
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* For more information on HTTP caching, see <a |
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* href="http://www.ietf.org/rfc/rfc2616.txt"><i>RFC 2616: Hypertext |
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* Transfer Protocol -- HTTP/1.1</i></a> |
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* |
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* @author Yingxian Wang |
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* @since 1.5 |
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*/ |
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public abstract class ResponseCache { |
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/** |
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* The system wide cache that provides access to a url |
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* caching mechanism. |
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* |
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* @see #setDefault(ResponseCache) |
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* @see #getDefault() |
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*/ |
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private static ResponseCache theResponseCache; |
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/** |
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* Gets the system-wide response cache. |
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* |
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* @throws SecurityException |
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* If a security manager has been installed and it denies |
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* {@link NetPermission}{@code ("getResponseCache")} |
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* |
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* @see #setDefault(ResponseCache) |
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* @return the system-wide {@code ResponseCache} |
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* @since 1.5 |
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*/ |
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2ee9017c7597
8136583: Core libraries should use blessed modifier order
martin
parents:
25859
diff
changeset
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public static synchronized ResponseCache getDefault() { |
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SecurityManager sm = System.getSecurityManager(); |
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if (sm != null) { |
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sm.checkPermission(SecurityConstants.GET_RESPONSECACHE_PERMISSION); |
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} |
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return theResponseCache; |
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} |
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/** |
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* Sets (or unsets) the system-wide cache. |
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* |
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* Note: non-standard procotol handlers may ignore this setting. |
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* |
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* @param responseCache The response cache, or |
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* {@code null} to unset the cache. |
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* |
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* @throws SecurityException |
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* If a security manager has been installed and it denies |
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* {@link NetPermission}{@code ("setResponseCache")} |
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* |
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* @see #getDefault() |
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* @since 1.5 |
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*/ |
|
32649
2ee9017c7597
8136583: Core libraries should use blessed modifier order
martin
parents:
25859
diff
changeset
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public static synchronized void setDefault(ResponseCache responseCache) { |
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SecurityManager sm = System.getSecurityManager(); |
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if (sm != null) { |
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sm.checkPermission(SecurityConstants.SET_RESPONSECACHE_PERMISSION); |
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} |
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theResponseCache = responseCache; |
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} |
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/** |
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* Retrieve the cached response based on the requesting uri, |
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* request method and request headers. Typically this method is |
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* called by the protocol handler before it sends out the request |
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* to get the network resource. If a cached response is returned, |
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* that resource is used instead. |
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* |
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* @param uri a {@code URI} used to reference the requested |
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* network resource |
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* @param rqstMethod a {@code String} representing the request |
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* method |
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* @param rqstHeaders - a Map from request header |
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* field names to lists of field values representing |
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* the current request headers |
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* @return a {@code CacheResponse} instance if available |
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* from cache, or null otherwise |
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* @throws IOException if an I/O error occurs |
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* @throws IllegalArgumentException if any one of the arguments is null |
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* |
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* @see java.net.URLConnection#setUseCaches(boolean) |
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* @see java.net.URLConnection#getUseCaches() |
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* @see java.net.URLConnection#setDefaultUseCaches(boolean) |
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* @see java.net.URLConnection#getDefaultUseCaches() |
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*/ |
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public abstract CacheResponse |
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get(URI uri, String rqstMethod, Map<String, List<String>> rqstHeaders) |
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throws IOException; |
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/** |
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* The protocol handler calls this method after a resource has |
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* been retrieved, and the ResponseCache must decide whether or |
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* not to store the resource in its cache. If the resource is to |
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* be cached, then put() must return a CacheRequest object which |
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* contains an OutputStream that the protocol handler will |
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* use to write the resource into the cache. If the resource is |
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* not to be cached, then put must return null. |
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* |
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* @param uri a {@code URI} used to reference the requested |
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* network resource |
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* @param conn - a URLConnection instance that is used to fetch |
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* the response to be cached |
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* @return a {@code CacheRequest} for recording the |
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* response to be cached. Null return indicates that |
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* the caller does not intend to cache the response. |
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* @throws IOException if an I/O error occurs |
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* @throws IllegalArgumentException if any one of the arguments is |
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* null |
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*/ |
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public abstract CacheRequest put(URI uri, URLConnection conn) throws IOException; |
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} |