/projects/ApacheHttpClient/src/java/org/apache/commons/httpclient/protocol/Protocol.java

/*

 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/protocol/Protocol.java,v 1.10 2004/04/18 23:51:38 jsdever Exp $

 * $Revision: 480424 $

 * $Date: 2006-11-29 11:26:49 +0530 (Wed, 29 Nov 2006) $

 *

 * ====================================================================

 *

 *  Licensed to the Apache Software Foundation (ASF) under one or more

 *  contributor license agreements.  See the NOTICE file distributed with

 *  this work for additional information regarding copyright ownership.

 *  The ASF licenses this file to You under the Apache License, Version 2.0

 *  (the "License"); you may not use this file except in compliance with

 *  the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 *  Unless required by applicable law or agreed to in writing, software

 *  distributed under the License is distributed on an "AS IS" BASIS,

 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 *  See the License for the specific language governing permissions and

 *  limitations under the License.

 * ====================================================================

 *

 * This software consists of voluntary contributions made by many

 * individuals on behalf of the Apache Software Foundation.  For more

 * information on the Apache Software Foundation, please see

 * <http://www.apache.org/>.

 *

 */

package org.apache.commons.httpclient.protocol;



import java.util.Collections;

import java.util.HashMap;

import java.util.Map;



import org.apache.commons.httpclient.util.LangUtils;



/**

 * A class to encapsulate the specifics of a protocol.  This class class also

 * provides the ability to customize the set and characteristics of the

 * protocols used.

 * 

 * <p>One use case for modifying the default set of protocols would be to set a

 * custom SSL socket factory.  This would look something like the following:

 * <pre> 

 * Protocol myHTTPS = new Protocol( "https", new MySSLSocketFactory(), 443 );

 * 

 * Protocol.registerProtocol( "https", myHTTPS );

 * </pre>

 *

 * @author Michael Becke 

 * @author Jeff Dever

 * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>

 *  

 * @since 2.0 

 */

public class Protocol {



    /** The available protocols */

    private static final Map PROTOCOLS = Collections.synchronizedMap(new HashMap());



    /**

     * Registers a new protocol with the given identifier.  If a protocol with

     * the given ID already exists it will be overridden.  This ID is the same

     * one used to retrieve the protocol from getProtocol(String).

     * 

     * @param id the identifier for this protocol

     * @param protocol the protocol to register

     * 

     * @see #getProtocol(String)

     */

    public static void registerProtocol(String id, Protocol protocol) {



        if (id == null) {

            throw new IllegalArgumentException("id is null");

        }

        if (protocol == null) {

            throw new IllegalArgumentException("protocol is null");

        }



        PROTOCOLS.put(id, protocol);

    }



    /**

     * Unregisters the protocol with the given ID.

     * 

     * @param id the ID of the protocol to remove

     */

    public static void unregisterProtocol(String id) {



        if (id == null) {

            throw new IllegalArgumentException("id is null");

        }



        PROTOCOLS.remove(id);

    }



    /**

     * Gets the protocol with the given ID.

     * 

     * @param id the protocol ID

     * 

     * @return Protocol a protocol

     * 

     * @throws IllegalStateException if a protocol with the ID cannot be found

     */

    public static Protocol getProtocol(String id) 

        throws IllegalStateException {



        if (id == null) {

            throw new IllegalArgumentException("id is null");

        }



        Protocol protocol = (Protocol) PROTOCOLS.get(id);



        if (protocol == null) {

            protocol = lazyRegisterProtocol(id);

        }



        return protocol;

    } 



    /**

     * Lazily registers the protocol with the given id.

     * 

     * @param id the protocol ID

     * 

     * @return the lazily registered protocol

     * 

     * @throws IllegalStateException if the protocol with id is not recognized

     */

    private static Protocol lazyRegisterProtocol(String id) 

        throws IllegalStateException {



        if ("http".equals(id)) {

            final Protocol http 

                = new Protocol("http", DefaultProtocolSocketFactory.getSocketFactory(), 80);

            Protocol.registerProtocol("http", http);

            return http;

        }



        if ("https".equals(id)) {

            final Protocol https 

                = new Protocol("https", SSLProtocolSocketFactory.getSocketFactory(), 443);

            Protocol.registerProtocol("https", https);

            return https;

        }



        throw new IllegalStateException("unsupported protocol: '" + id + "'");

    }

    



    /** the scheme of this protocol (e.g. http, https) */

    private String scheme;

    

    /** The socket factory for this protocol */

    private ProtocolSocketFactory socketFactory;

    

    /** The default port for this protocol */

    private int defaultPort;

    

    /** True if this protocol is secure */

    private boolean secure;

  

    /**

     * Constructs a new Protocol. Whether the created protocol is secure depends on

     * the class of <code>factory</code>.

     * 

     * @param scheme the scheme (e.g. http, https)

     * @param factory the factory for creating sockets for communication using

     * this protocol

     * @param defaultPort the port this protocol defaults to

     */

    public Protocol(String scheme, ProtocolSocketFactory factory, int defaultPort) {

        

        if (scheme == null) {

            throw new IllegalArgumentException("scheme is null");

        }

        if (factory == null) {

            throw new IllegalArgumentException("socketFactory is null");

        }

        if (defaultPort <= 0) {

            throw new IllegalArgumentException("port is invalid: " + defaultPort);

        }

        

        this.scheme = scheme;

        this.socketFactory = factory;

        this.defaultPort = defaultPort;

        this.secure = (factory instanceof SecureProtocolSocketFactory);

    }

    

    /**

     * Constructs a new Protocol. Whether the created protocol is secure depends on

     * the class of <code>factory</code>.

     *

     * @param scheme the scheme (e.g. http, https)

     * @param factory the factory for creating sockets for communication using

     * this protocol

     * @param defaultPort the port this protocol defaults to

     * @deprecated Use the constructor that uses ProtocolSocketFactory, this version of

     * the constructor is only kept for backwards API compatibility.

     */

    public Protocol(String scheme, 

        SecureProtocolSocketFactory factory, int defaultPort) {

        this(scheme, (ProtocolSocketFactory) factory, defaultPort);   

    }    

    

    /**

     * Returns the defaultPort.

     * @return int

     */

    public int getDefaultPort() {

        return defaultPort;

    }



    /**

     * Returns the socketFactory.  If secure the factory is a

     * SecureProtocolSocketFactory.

     * @return SocketFactory

     */

    public ProtocolSocketFactory getSocketFactory() {

        return socketFactory;

    }



    /**

     * Returns the scheme.

     * @return The scheme

     */

    public String getScheme() {

        return scheme;

    }



    /**

     * Returns true if this protocol is secure

     * @return true if this protocol is secure

     */

    public boolean isSecure() {

        return secure;

    }

    

    /**

     * Resolves the correct port for this protocol.  Returns the given port if

     * valid or the default port otherwise.

     * 

     * @param port the port to be resolved

     * 

     * @return the given port or the defaultPort

     */

    public int resolvePort(int port) {

        return port <= 0 ? getDefaultPort() : port;

    }



    /**

     * Return a string representation of this object.

     * @return a string representation of this object.

     */

    public String toString() {

        return scheme + ":" + defaultPort;

    }

    

    /**

     * Return true if the specified object equals this object.

     * @param obj The object to compare against.

     * @return true if the objects are equal.

     */

    public boolean equals(Object obj) {

        

        if (obj instanceof Protocol) {

            

            Protocol p = (Protocol) obj;

            

            return (

                defaultPort == p.getDefaultPort()

                && scheme.equalsIgnoreCase(p.getScheme())

                && secure == p.isSecure()

                && socketFactory.equals(p.getSocketFactory()));

            

        } else {

            return false;

        }

        

    }



    /**

     * Return a hash code for this object

     * @return The hash code.

     */

    public int hashCode() {

        int hash = LangUtils.HASH_SEED;

        hash = LangUtils.hashCode(hash, this.defaultPort);

        hash = LangUtils.hashCode(hash, this.scheme.toLowerCase());

        hash = LangUtils.hashCode(hash, this.secure);

        hash = LangUtils.hashCode(hash, this.socketFactory);

        return hash;

    }

}