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 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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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 final static 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();
 }
}