| /* |
| * Copyright (c) 2003, 2006, 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.io.IOException; |
| import java.util.List; |
| import sun.security.util.SecurityConstants; |
| |
| /** |
| * Selects the proxy server to use, if any, when connecting to the |
| * network resource referenced by a URL. A proxy selector is a |
| * concrete sub-class of this class and is registered by invoking the |
| * {@link java.net.ProxySelector#setDefault setDefault} method. The |
| * currently registered proxy selector can be retrieved by calling |
| * {@link java.net.ProxySelector#getDefault getDefault} method. |
| * |
| * <p> When a proxy selector is registered, for instance, a subclass |
| * of URLConnection class should call the {@link #select select} |
| * method for each URL request so that the proxy selector can decide |
| * if a direct, or proxied connection should be used. The {@link |
| * #select select} method returns an iterator over a collection with |
| * the preferred connection approach. |
| * |
| * <p> If a connection cannot be established to a proxy (PROXY or |
| * SOCKS) servers then the caller should call the proxy selector's |
| * {@link #connectFailed connectFailed} method to notify the proxy |
| * selector that the proxy server is unavailable. </p> |
| * |
| * <P>The default proxy selector does enforce a |
| * <a href="doc-files/net-properties.html#Proxies">set of System Properties</a> |
| * related to proxy settings.</P> |
| * |
| * @author Yingxian Wang |
| * @author Jean-Christophe Collet |
| * @since 1.5 |
| */ |
| public abstract class ProxySelector { |
| /** |
| * The system wide proxy selector that selects the proxy server to |
| * use, if any, when connecting to a remote object referenced by |
| * an URL. |
| * |
| * @see #setDefault(ProxySelector) |
| */ |
| private static ProxySelector theProxySelector; |
| |
| static { |
| try { |
| Class c = Class.forName("sun.net.spi.DefaultProxySelector"); |
| if (c != null && ProxySelector.class.isAssignableFrom(c)) { |
| theProxySelector = (ProxySelector) c.newInstance(); |
| } |
| } catch (Exception e) { |
| theProxySelector = null; |
| } |
| } |
| |
| /** |
| * Gets the system-wide proxy selector. |
| * |
| * @throws SecurityException |
| * If a security manager has been installed and it denies |
| * {@link NetPermission}<tt>("getProxySelector")</tt> |
| * @see #setDefault(ProxySelector) |
| * @return the system-wide <code>ProxySelector</code> |
| * @since 1.5 |
| */ |
| public static ProxySelector getDefault() { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) { |
| sm.checkPermission(SecurityConstants.GET_PROXYSELECTOR_PERMISSION); |
| } |
| return theProxySelector; |
| } |
| |
| /** |
| * Sets (or unsets) the system-wide proxy selector. |
| * |
| * Note: non-standard protocol handlers may ignore this setting. |
| * |
| * @param ps The HTTP proxy selector, or |
| * <code>null</code> to unset the proxy selector. |
| * |
| * @throws SecurityException |
| * If a security manager has been installed and it denies |
| * {@link NetPermission}<tt>("setProxySelector")</tt> |
| * |
| * @see #getDefault() |
| * @since 1.5 |
| */ |
| public static void setDefault(ProxySelector ps) { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) { |
| sm.checkPermission(SecurityConstants.SET_PROXYSELECTOR_PERMISSION); |
| } |
| theProxySelector = ps; |
| } |
| |
| /** |
| * Selects all the applicable proxies based on the protocol to |
| * access the resource with and a destination address to access |
| * the resource at. |
| * The format of the URI is defined as follow: |
| * <UL> |
| * <LI>http URI for http connections</LI> |
| * <LI>https URI for https connections |
| * <LI>ftp URI for ftp connections</LI> |
| * <LI><code>socket://host:port</code><br> |
| * for tcp client sockets connections</LI> |
| * </UL> |
| * |
| * @param uri |
| * The URI that a connection is required to |
| * |
| * @return a List of Proxies. Each element in the |
| * the List is of type |
| * {@link java.net.Proxy Proxy}; |
| * when no proxy is available, the list will |
| * contain one element of type |
| * {@link java.net.Proxy Proxy} |
| * that represents a direct connection. |
| * @throws IllegalArgumentException if the argument is null |
| */ |
| public abstract List<Proxy> select(URI uri); |
| |
| /** |
| * Called to indicate that a connection could not be established |
| * to a proxy/socks server. An implementation of this method can |
| * temporarily remove the proxies or reorder the sequence of |
| * proxies returned by {@link #select(URI)}, using the address |
| * and the IOException caught when trying to connect. |
| * |
| * @param uri |
| * The URI that the proxy at sa failed to serve. |
| * @param sa |
| * The socket address of the proxy/SOCKS server |
| * |
| * @param ioe |
| * The I/O exception thrown when the connect failed. |
| * @throws IllegalArgumentException if either argument is null |
| */ |
| public abstract void connectFailed(URI uri, SocketAddress sa, IOException ioe); |
| } |
