001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied. See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019
020 package javax.mail;
021
022 import java.net.InetAddress;
023 import java.net.UnknownHostException;
024 import java.util.List;
025 import java.util.Vector;
026
027 import javax.mail.event.ConnectionEvent;
028 import javax.mail.event.ConnectionListener;
029 import javax.mail.event.MailEvent;
030
031 /**
032 * @version $Rev: 597092 $ $Date: 2007-11-21 09:02:38 -0500 (Wed, 21 Nov 2007) $
033 */
034 public abstract class Service {
035 /**
036 * The session from which this service was created.
037 */
038 protected Session session;
039 /**
040 * The URLName of this service
041 */
042 protected URLName url;
043 /**
044 * Debug flag for this service, set from the Session's debug flag.
045 */
046 protected boolean debug;
047
048 private boolean connected;
049 private final Vector connectionListeners = new Vector(2);
050 // the EventQueue spins off a new thread, so we only create this
051 // if we have actual listeners to dispatch an event to.
052 private EventQueue queue = null;
053 // when returning the URL, we need to ensure that the password and file information is
054 // stripped out.
055 private URLName exposedUrl;
056
057 /**
058 * Construct a new Service.
059 * @param session the session from which this service was created
060 * @param url the URLName of this service
061 */
062 protected Service(Session session, URLName url) {
063 this.session = session;
064 this.url = url;
065 this.debug = session.getDebug();
066 }
067
068 /**
069 * A generic connect method that takes no parameters allowing subclasses
070 * to implement an appropriate authentication scheme.
071 * The default implementation calls <code>connect(null, null, null)</code>
072 * @throws AuthenticationFailedException if authentication fails
073 * @throws MessagingException for other failures
074 */
075 public void connect() throws MessagingException {
076 connect(null, null, null);
077 }
078
079 /**
080 * Connect to the specified host using a simple username/password authenticaion scheme
081 * and the default port.
082 * The default implementation calls <code>connect(host, -1, user, password)</code>
083 *
084 * @param host the host to connect to
085 * @param user the user name
086 * @param password the user's password
087 * @throws AuthenticationFailedException if authentication fails
088 * @throws MessagingException for other failures
089 */
090 public void connect(String host, String user, String password) throws MessagingException {
091 connect(host, -1, user, password);
092 }
093
094 /**
095 * Connect to the specified host using a simple username/password authenticaion scheme
096 * and the default host and port.
097 * The default implementation calls <code>connect(host, -1, user, password)</code>
098 *
099 * @param user the user name
100 * @param password the user's password
101 * @throws AuthenticationFailedException if authentication fails
102 * @throws MessagingException for other failures
103 */
104 public void connect(String user, String password) throws MessagingException {
105 connect(null, -1, user, password);
106 }
107
108 /**
109 * Connect to the specified host at the specified port using a simple username/password authenticaion scheme.
110 *
111 * If this Service is already connected, an IllegalStateException is thrown.
112 *
113 * @param host the host to connect to
114 * @param port the port to connect to; pass -1 to use the default for the protocol
115 * @param user the user name
116 * @param password the user's password
117 * @throws AuthenticationFailedException if authentication fails
118 * @throws MessagingException for other failures
119 * @throws IllegalStateException if this service is already connected
120 */
121 public void connect(String host, int port, String user, String password) throws MessagingException {
122
123 if (isConnected()) {
124 throw new IllegalStateException("Already connected");
125 }
126
127 // before we try to connect, we need to derive values for some parameters that may not have
128 // been explicitly specified. For example, the normal connect() method leaves us to derive all
129 // of these from other sources. Some of the values are derived from our URLName value, others
130 // from session parameters. We need to go through all of these to develop a set of values we
131 // can connect with.
132
133 // this is the protocol we're connecting with. We use this largely to derive configured values from
134 // session properties.
135 String protocol = null;
136
137 // if we're working with the URL form, then we can retrieve the protocol from the URL.
138 if (url != null) {
139 protocol = url.getProtocol();
140 }
141
142 // if the port is -1, see if we have an override from url.
143 if (port == -1) {
144 if (protocol != null) {
145 port = url.getPort();
146 }
147 }
148
149 // now try to derive values for any of the arguments we've been given as defaults
150 if (host == null) {
151 // first choice is from the url, if we have
152 if (url != null) {
153 host = url.getHost();
154 // it is possible that this could return null (rare). If it does, try to get a
155 // value from a protocol specific session variable.
156 if (host == null) {
157 if (protocol != null) {
158 host = session.getProperty("mail." + protocol + ".host");
159 }
160 }
161 }
162 // this may still be null...get the global mail property
163 if (host == null) {
164 host = session.getProperty("mail.host");
165 }
166 }
167
168 // ok, go after userid information next.
169 if (user == null) {
170 // first choice is from the url, if we have
171 if (url != null) {
172 user = url.getUsername();
173 // make sure we get the password from the url, if we can.
174 if (password == null) {
175 password = url.getPassword();
176 }
177 // user still null? We have several levels of properties to try yet
178 if (user == null) {
179 if (protocol != null) {
180 user = session.getProperty("mail." + protocol + ".user");
181 }
182 }
183 }
184
185 // this may still be null...get the global mail property
186 if (user == null) {
187 user = session.getProperty("mail.user");
188 }
189
190 // finally, we try getting the system defined user name
191 try {
192 user = System.getProperty("user.name");
193 } catch (SecurityException e) {
194 // we ignore this, and just us a null username.
195 }
196 }
197 // if we have an explicitly given user name, we need to see if this matches the url one and
198 // grab the password from there.
199 else {
200 if (url != null && user.equals(url.getUsername())) {
201 password = url.getPassword();
202 }
203 }
204
205 // we need to update the URLName associated with this connection once we have all of the information,
206 // which means we also need to propogate the file portion of the URLName if we have this form when
207 // we start.
208 String file = null;
209 if (url != null) {
210 file = url.getFile();
211 }
212
213 // see if we have cached security information to use. If this is not cached, we'll save it
214 // after we successfully connect.
215 boolean cachePassword = false;
216
217
218 // still have a null password to this point, and using a url form?
219 if (password == null && url != null) {
220 // construct a new URL, filling in any pieces that may have been explicitly specified.
221 setURLName(new URLName(protocol, host, port, file, user, password));
222 // now see if we have a saved password from a previous request.
223 PasswordAuthentication cachedPassword = session.getPasswordAuthentication(getURLName());
224
225 // if we found a saved one, see if we need to get any the pieces from here.
226 if (cachedPassword != null) {
227 // not even a resolved userid? Then use both bits.
228 if (user == null) {
229 user = cachedPassword.getUserName();
230 password = cachedPassword.getPassword();
231 }
232 // our user name must match the cached name to be valid.
233 else if (user.equals(cachedPassword.getUserName())) {
234 password = cachedPassword.getPassword();
235 }
236 }
237 else
238 {
239 // nothing found in the cache, so we need to save this if we can connect successfully.
240 cachePassword = true;
241 }
242 }
243
244 // we've done our best up to this point to obtain all of the information needed to make the
245 // connection. Now we pass this off to the protocol handler to see if it works. If we get a
246 // connection failure, we may need to prompt for a password before continuing.
247 try {
248 connected = protocolConnect(host, port, user, password);
249 }
250 catch (AuthenticationFailedException e) {
251 }
252
253 if (!connected) {
254 InetAddress ipAddress = null;
255
256 try {
257 ipAddress = InetAddress.getByName(host);
258 } catch (UnknownHostException e) {
259 }
260
261 // now ask the session to try prompting for a password.
262 PasswordAuthentication promptPassword = session.requestPasswordAuthentication(ipAddress, port, protocol, null, user);
263
264 // if we were able to obtain new information from the session, then try again using the
265 // provided information .
266 if (promptPassword != null) {
267 user = promptPassword.getUserName();
268 password = promptPassword.getPassword();
269 }
270
271 connected = protocolConnect(host, port, user, password);
272 }
273
274
275 // if we're still not connected, then this is an exception.
276 if (!connected) {
277 throw new AuthenticationFailedException();
278 }
279
280 // the URL name needs to reflect the most recent information.
281 setURLName(new URLName(protocol, host, port, file, user, password));
282
283 // we need to update the global password cache with this information.
284 if (cachePassword) {
285 session.setPasswordAuthentication(getURLName(), new PasswordAuthentication(user, password));
286 }
287
288 // we're now connected....broadcast this to any interested parties.
289 setConnected(connected);
290 notifyConnectionListeners(ConnectionEvent.OPENED);
291 }
292
293 /**
294 * Attempt the protocol-specific connection; subclasses should override this to establish
295 * a connection in the appropriate manner.
296 *
297 * This method should return true if the connection was established.
298 * It may return false to cause the {@link #connect(String, int, String, String)} method to
299 * reattempt the connection after trying to obtain user and password information from the user.
300 * Alternatively it may throw a AuthenticatedFailedException to abandon the conection attempt.
301 *
302 * @param host The target host name of the service.
303 * @param port The connection port for the service.
304 * @param user The user name used for the connection.
305 * @param password The password used for the connection.
306 *
307 * @return true if a connection was established, false if there was authentication
308 * error with the connection.
309 * @throws AuthenticationFailedException
310 * if authentication fails
311 * @throws MessagingException
312 * for other failures
313 */
314 protected boolean protocolConnect(String host, int port, String user, String password) throws MessagingException {
315 return false;
316 }
317
318 /**
319 * Check if this service is currently connected.
320 * The default implementation simply returns the value of a private boolean field;
321 * subclasses may wish to override this method to verify the physical connection.
322 *
323 * @return true if this service is connected
324 */
325 public boolean isConnected() {
326 return connected;
327 }
328
329 /**
330 * Notification to subclasses that the connection state has changed.
331 * This method is called by the connect() and close() methods to indicate state change;
332 * subclasses should also call this method if the connection is automatically closed
333 * for some reason.
334 *
335 * @param connected the connection state
336 */
337 protected void setConnected(boolean connected) {
338 this.connected = connected;
339 }
340
341 /**
342 * Close this service and terminate its physical connection.
343 * The default implementation simply calls setConnected(false) and then
344 * sends a CLOSED event to all registered ConnectionListeners.
345 * Subclasses overriding this method should still ensure it is closed; they should
346 * also ensure that it is called if the connection is closed automatically, for
347 * for example in a finalizer.
348 *
349 *@throws MessagingException if there were errors closing; the connection is still closed
350 */
351 public void close() throws MessagingException {
352 setConnected(false);
353 notifyConnectionListeners(ConnectionEvent.CLOSED);
354 }
355
356 /**
357 * Return a copy of the URLName representing this service with the password and file information removed.
358 *
359 * @return the URLName for this service
360 */
361 public URLName getURLName() {
362 // if we haven't composed the URL version we hand out, create it now. But only if we really
363 // have a URL.
364 if (exposedUrl == null) {
365 if (url != null) {
366 exposedUrl = new URLName(url.getProtocol(), url.getHost(), url.getPort(), null, url.getUsername(), null);
367 }
368 }
369 return exposedUrl;
370 }
371
372 /**
373 * Set the url field.
374 * @param url the new value
375 */
376 protected void setURLName(URLName url) {
377 this.url = url;
378 }
379
380 public void addConnectionListener(ConnectionListener listener) {
381 connectionListeners.add(listener);
382 }
383
384 public void removeConnectionListener(ConnectionListener listener) {
385 connectionListeners.remove(listener);
386 }
387
388 protected void notifyConnectionListeners(int type) {
389 queueEvent(new ConnectionEvent(this, type), connectionListeners);
390 }
391
392 public String toString() {
393 // NOTE: We call getURLName() rather than use the URL directly
394 // because the get method strips out the password information.
395 URLName url = getURLName();
396
397 return url == null ? super.toString() : url.toString();
398 }
399
400 protected void queueEvent(MailEvent event, Vector listeners) {
401 // if there are no listeners to dispatch this to, don't put it on the queue.
402 // This allows us to delay creating the queue (and its new thread) until
403 // we
404 if (listeners.isEmpty()) {
405 return;
406 }
407 // first real event? Time to get the queue kicked off.
408 if (queue == null) {
409 queue = new EventQueue();
410 }
411 // tee it up and let it rip.
412 queue.queueEvent(event, (List)listeners.clone());
413 }
414
415 protected void finalize() throws Throwable {
416 // stop our event queue if we had to create one
417 if (queue != null) {
418 queue.stop();
419 }
420 connectionListeners.clear();
421 super.finalize();
422 }
423
424
425 /**
426 * Package scope utility method to allow Message instances
427 * access to the Service's session.
428 *
429 * @return The Session the service is associated with.
430 */
431 Session getSession() {
432 return session;
433 }
434 }