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; /** * This class represents a proxy setting, typically a type (http, socks) and * a socket address. * A {@code Proxy} is an immutable object. * * @see java.net.ProxySelector * @author Yingxian Wang * @author Jean-Christophe Collet * @since 1.5 */ public class Proxy { /** * Represents the proxy type. * * @since 1.5 */ public enum Type { /** * Represents a direct connection, or the absence of a proxy. */ DIRECT, /** * Represents proxy for high level protocols such as HTTP or FTP. */ HTTP, /** * Represents a SOCKS (V4 or V5) proxy. */ SOCKS }; private Type type; private SocketAddress sa; /** * A proxy setting that represents a {@code DIRECT} connection, * basically telling the protocol handler not to use any proxying. * Used, for instance, to create sockets bypassing any other global * proxy settings (like SOCKS): * <P> * {@code Socket s = new Socket(Proxy.NO_PROXY);} * */ public static final Proxy NO_PROXY = new Proxy(); // Creates the proxy that represents a {@code DIRECT} connection. private Proxy() { type = Type.DIRECT; sa = null; } /** * Creates an entry representing a PROXY connection. * Certain combinations are illegal. For instance, for types Http, and * Socks, a SocketAddress <b>must</b> be provided. * <P> * Use the {@code Proxy.NO_PROXY} constant * for representing a direct connection. * * @param type the {@code Type} of the proxy * @param sa the {@code SocketAddress} for that proxy * @throws IllegalArgumentException when the type and the address are * incompatible */ public Proxy(Type type, SocketAddress sa) { if ((type == Type.DIRECT) || !(sa instanceof InetSocketAddress)) throw new IllegalArgumentException("type " + type + " is not compatible with address " + sa); this.type = type; this.sa = sa; } /** * Returns the proxy type. * * @return a Type representing the proxy type */ public Type type() { return type; } /** * Returns the socket address of the proxy, or * {@code null} if its a direct connection. * * @return a {@code SocketAddress} representing the socket end * point of the proxy */ public SocketAddress address() { return sa; } /** * Constructs a string representation of this Proxy. * This String is constructed by calling toString() on its type * and concatenating " @ " and the toString() result from its address * if its type is not {@code DIRECT}. * * @return a string representation of this object. */ public String toString() { if (type() == Type.DIRECT) return "DIRECT"; return type() + " @ " + address(); } /** * Compares this object against the specified object. * The result is {@code true} if and only if the argument is * not {@code null} and it represents the same proxy as * this object. * <p> * Two instances of {@code Proxy} represent the same * address if both the SocketAddresses and type are equal. * * @param obj the object to compare against. * @return {@code true} if the objects are the same; * {@code false} otherwise. * @see java.net.InetSocketAddress#equals(java.lang.Object) */ public final boolean equals(Object obj) { if (obj == null || !(obj instanceof Proxy)) return false; Proxy p = (Proxy) obj; if (p.type() == type()) { if (address() == null) { return (p.address() == null); } else return address().equals(p.address()); } return false; } /** * Returns a hashcode for this Proxy. * * @return a hash code value for this Proxy. */ public final int hashCode() { if (address() == null) return type().hashCode(); return type().hashCode() + address().hashCode(); } }