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1   /*
2    * $Header: /home/cvs/jakarta-commons/httpclient/src/java/org/apache/commons/httpclient/protocol/Protocol.java,v 1.5.2.2 2004/02/22 18:21:16 olegk Exp $
3    * $Revision: 1.5.2.2 $
4    * $Date: 2004/02/22 18:21:16 $
5    *
6    * ====================================================================
7    *
8    *  Copyright 2002-2004 The Apache Software Foundation
9    *
10   *  Licensed under the Apache License, Version 2.0 (the "License");
11   *  you may not use this file except in compliance with the License.
12   *  You may obtain a copy of the License at
13   *
14   *      http://www.apache.org/licenses/LICENSE-2.0
15   *
16   *  Unless required by applicable law or agreed to in writing, software
17   *  distributed under the License is distributed on an "AS IS" BASIS,
18   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19   *  See the License for the specific language governing permissions and
20   *  limitations under the License.
21   * ====================================================================
22   *
23   * This software consists of voluntary contributions made by many
24   * individuals on behalf of the Apache Software Foundation.  For more
25   * information on the Apache Software Foundation, please see
26   * <http://www.apache.org/>.
27   *
28   * [Additional notices, if required by prior licensing conditions]
29   *
30   */
31  package org.apache.commons.httpclient.protocol;
32  
33  import java.util.Collections;
34  import java.util.HashMap;
35  import java.util.Map;
36  
37  /***
38   * A class to encapsulate the specifics of a protocol.  This class class also
39   * provides the ability to customize the set and characteristics of the
40   * protocols used.
41   * 
42   * <p>One use case for modifying the default set of protocols would be to set a
43   * custom SSL socket factory.  This would look something like the following:
44   * <pre> 
45   * Protocol myHTTPS = new Protocol( "https", new MySSLSocketFactory(), 443 );
46   * 
47   * Protocol.registerProtocol( "https", myHTTPS );
48   * </pre>
49   *
50   * @author Michael Becke 
51   * @author Jeff Dever
52   * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
53   *  
54   * @since 2.0 
55   */
56  public class Protocol {
57  
58      /*** The available protocols */
59      private static final Map PROTOCOLS = Collections.synchronizedMap(new HashMap());
60  
61      /***
62       * Registers a new protocol with the given identifier.  If a protocol with
63       * the given ID already exists it will be overridden.  This ID is the same
64       * one used to retrieve the protocol from getProtocol(String).
65       * 
66       * @param id the identifier for this protocol
67       * @param protocol the protocol to register
68       * 
69       * @see #getProtocol(String)
70       */
71      public static void registerProtocol(String id, Protocol protocol) {
72  
73          if (id == null) {
74              throw new IllegalArgumentException("id is null");
75          }
76          if (protocol == null) {
77              throw new IllegalArgumentException("protocol is null");
78          }
79  
80          PROTOCOLS.put(id, protocol);
81      }
82  
83      /***
84       * Unregisters the protocol with the given ID.
85       * 
86       * @param id the ID of the protocol to remove
87       */
88      public static void unregisterProtocol(String id) {
89  
90          if (id == null) {
91              throw new IllegalArgumentException("id is null");
92          }
93  
94          PROTOCOLS.remove(id);
95      }
96  
97      /***
98       * Gets the protocol with the given ID.
99       * 
100      * @param id the protocol ID
101      * 
102      * @return Protocol a protocol
103      * 
104      * @throws IllegalStateException if a protocol with the ID cannot be found
105      */
106     public static Protocol getProtocol(String id) 
107         throws IllegalStateException {
108 
109         if (id == null) {
110             throw new IllegalArgumentException("id is null");
111         }
112 
113         Protocol protocol = (Protocol) PROTOCOLS.get(id);
114 
115         if (protocol == null) {
116             protocol = lazyRegisterProtocol(id);
117         }
118 
119         return protocol;
120     } 
121 
122     /***
123      * Lazily registers the protocol with the given id.
124      * 
125      * @param id the protocol ID
126      * 
127      * @return the lazily registered protocol
128      * 
129      * @throws IllegalStateException if the protocol with id is not recognized
130      */
131     private static Protocol lazyRegisterProtocol(String id) 
132         throws IllegalStateException {
133 
134         if ("http".equals(id)) {
135             final Protocol http 
136                 = new Protocol("http", DefaultProtocolSocketFactory.getSocketFactory(), 80);
137             Protocol.registerProtocol("http", http);
138             return http;
139         }
140 
141         if ("https".equals(id)) {
142             final Protocol https 
143                 = new Protocol("https", SSLProtocolSocketFactory.getSocketFactory(), 443);
144             Protocol.registerProtocol("https", https);
145             return https;
146         }
147 
148         throw new IllegalStateException("unsupported protocol: '" + id + "'");
149     }
150     
151 
152     /*** the scheme of this protocol (e.g. http, https) */
153     private String scheme;
154     
155     /*** The socket factory for this protocol */
156     private ProtocolSocketFactory socketFactory;
157     
158     /*** The default port for this protocol */
159     private int defaultPort;
160     
161     /*** True if this protocol is secure */
162     private boolean secure;
163   
164     /***
165      * Constructs a new Protocol.  The created protcol is insecure.
166      * 
167      * @param scheme the scheme (e.g. http, https)
168      * @param factory the factory for creating sockets for communication using
169      * this protocol
170      * @param defaultPort the port this protocol defaults to
171      */
172     public Protocol(String scheme, ProtocolSocketFactory factory, int defaultPort) {
173         
174         if (scheme == null) {
175             throw new IllegalArgumentException("scheme is null");
176         }
177         if (factory == null) {
178             throw new IllegalArgumentException("socketFactory is null");
179         }
180         if (defaultPort <= 0) {
181             throw new IllegalArgumentException("port is invalid: " + defaultPort);
182         }
183         
184         this.scheme = scheme;
185         this.socketFactory = factory;
186         this.defaultPort = defaultPort;
187         this.secure = false;
188     }
189     
190     /***
191      * Constructs a new Protocol.  The created protcol is secure.
192      *
193      * @param scheme the scheme (e.g. http, https)
194      * @param factory the factory for creating sockets for communication using
195      * this protocol
196      * @param defaultPort the port this protocol defaults to
197      */
198     public Protocol(String scheme, 
199         SecureProtocolSocketFactory factory, int defaultPort) {
200         
201         if (scheme == null) {
202             throw new IllegalArgumentException("scheme is null");
203         }
204         if (factory == null) {
205             throw new IllegalArgumentException("socketFactory is null");
206         }
207         if (defaultPort <= 0) {
208             throw new IllegalArgumentException("port is invalid: " + defaultPort);
209         }
210 
211         this.scheme = scheme;
212         this.socketFactory = factory;
213         this.defaultPort = defaultPort;
214         this.secure = true;        
215     }
216 
217     /***
218      * Returns the defaultPort.
219      * @return int
220      */
221     public int getDefaultPort() {
222         return defaultPort;
223     }
224 
225     /***
226      * Returns the socketFactory.  If secure the factory is a
227      * SecureProtocolSocketFactory.
228      * @return SocketFactory
229      */
230     public ProtocolSocketFactory getSocketFactory() {
231         return socketFactory;
232     }
233 
234     /***
235      * Returns the scheme.
236      * @return The scheme
237      */
238     public String getScheme() {
239         return scheme;
240     }
241 
242     /***
243      * Returns true if this protocol is secure
244      * @return true if this protocol is secure
245      */
246     public boolean isSecure() {
247         return secure;
248     }
249     
250     /***
251      * Resolves the correct port for this protocol.  Returns the given port if
252      * valid or the default port otherwise.
253      * 
254      * @param port the port to be resolved
255      * 
256      * @return the given port or the defaultPort
257      */
258     public int resolvePort(int port) {
259         return port <= 0 ? getDefaultPort() : port;
260     }
261 
262     /***
263      * Return a string representation of this object.
264      * @return a string representation of this object.
265      */
266     public String toString() {
267         return scheme + ":" + defaultPort;
268     }
269     
270     /***
271      * Return true if the specified object equals this object.
272      * @param obj The object to compare against.
273      * @return true if the objects are equal.
274      */
275     public boolean equals(Object obj) {
276         
277         if (obj instanceof Protocol) {
278             
279             Protocol p = (Protocol) obj;
280             
281             return (
282                 defaultPort == p.getDefaultPort()
283                 && scheme.equalsIgnoreCase(p.getScheme())
284                 && secure == p.isSecure()
285                 && socketFactory.equals(p.getSocketFactory()));
286             
287         } else {
288             return false;
289         }
290         
291     }
292 
293     /***
294      * Return a hash code for this object
295      * @return The hash code.
296      */
297     public int hashCode() {
298         return scheme.hashCode();
299     }
300 }