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package java.net;


This class represents a proxy setting, typically a type (http, socks) and a socket address. A Proxy is an immutable object. 
Author:Yingxian Wang, Jean-Christophe Collet
See Also:
Since:  1.5
/**
 * 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
/**
     * Represents the proxy type.
     *
     * @since 1.5
     */
    public enum Type {
        
Represents a direct connection, or the absence of a proxy.

/**
         * Represents a direct connection, or the absence of a proxy.
         */
        DIRECT,
        
Represents proxy for high level protocols such as HTTP or FTP.

/**
         * Represents proxy for high level protocols such as HTTP or FTP.
         */
        HTTP,
        
Represents a SOCKS (V4 or V5) proxy.

/**
         * Represents a SOCKS (V4 or V5) proxy.
         */
        SOCKS
    };

    private Type type;
    private SocketAddress sa;

    
A proxy setting that represents a 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): 
 Socket s = new Socket(Proxy.NO_PROXY); 
/**
     * 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 must be provided.

 Use the Proxy.NO_PROXY constant for representing a direct connection. 
Params:
  • type – the Type of the proxy
  • sa – the SocketAddress for that proxy
Throws:
/**
     * 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.

Returns:a Type representing the proxy type
/**
     * Returns the proxy type.
     *
     * @return a Type representing the proxy type
     */
    public Type type() {
        return type;
    }

    
Returns the socket address of the proxy, or null if its a direct connection. 
Returns:a SocketAddress representing the socket end point of the proxy
/**
     * 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 DIRECT. 
Returns: a string representation of this object.
/**
     * 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 true if and only if the argument is not null and it represents the same proxy as this object. 
 Two instances of Proxy represent the same address if both the SocketAddresses and type are equal. 
Params:
  • obj –   the object to compare against.
See Also:
Returns: true if the objects are the same; false otherwise.
/**
     * 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.

Returns: a hash code value for this Proxy.
/**
     * 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();
    }
}