1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.net.pop3;
19
20 import java.io.BufferedReader;
21 import java.io.BufferedWriter;
22 import java.io.EOFException;
23 import java.io.IOException;
24 import java.io.InputStreamReader;
25 import java.io.OutputStreamWriter;
26 import java.util.Enumeration;
27 import java.util.Vector;
28
29 import org.apache.commons.net.MalformedServerReplyException;
30 import org.apache.commons.net.ProtocolCommandListener;
31 import org.apache.commons.net.ProtocolCommandSupport;
32 import org.apache.commons.net.SocketClient;
33
34 /***
35 * The POP3 class is not meant to be used by itself and is provided
36 * only so that you may easily implement your own POP3 client if
37 * you so desire. If you have no need to perform your own implementation,
38 * you should use {@link org.apache.commons.net.pop3.POP3Client}.
39 * <p>
40 * Rather than list it separately for each method, we mention here that
41 * every method communicating with the server and throwing an IOException
42 * can also throw a
43 * {@link org.apache.commons.net.MalformedServerReplyException}
44 * , which is a subclass
45 * of IOException. A MalformedServerReplyException will be thrown when
46 * the reply received from the server deviates enough from the protocol
47 * specification that it cannot be interpreted in a useful manner despite
48 * attempts to be as lenient as possible.
49 * <p>
50 * <p>
51 * @author Daniel F. Savarese
52 * @see POP3Client
53 * @see org.apache.commons.net.MalformedServerReplyException
54 ***/
55
56 public class POP3 extends SocketClient
57 {
58 /*** The default POP3 port. Set to 110 according to RFC 1288. ***/
59 public static final int DEFAULT_PORT = 110;
60 /***
61 * A constant representing the state where the client is not yet connected
62 * to a POP3 server.
63 ***/
64 public static final int DISCONNECTED_STATE = -1;
65 /*** A constant representing the POP3 authorization state. ***/
66 public static final int AUTHORIZATION_STATE = 0;
67 /*** A constant representing the POP3 transaction state. ***/
68 public static final int TRANSACTION_STATE = 1;
69 /*** A constant representing the POP3 update state. ***/
70 public static final int UPDATE_STATE = 2;
71
72 static final String _OK = "+OK";
73 static final String _ERROR = "-ERR";
74
75 // We have to ensure that the protocol communication is in ASCII
76 // but we use ISO-8859-1 just in case 8-bit characters cross
77 // the wire.
78 private static final String __DEFAULT_ENCODING = "ISO-8859-1";
79
80 private int __popState;
81 private BufferedWriter __writer;
82 private StringBuffer __commandBuffer;
83
84 BufferedReader _reader;
85 int _replyCode;
86 String _lastReplyLine;
87 Vector<String> _replyLines;
88
89 /***
90 * A ProtocolCommandSupport object used to manage the registering of
91 * ProtocolCommandListeners and te firing of ProtocolCommandEvents.
92 ***/
93 protected ProtocolCommandSupport _commandSupport_;
94
95 /***
96 * The default POP3Client constructor. Initializes the state
97 * to <code>DISCONNECTED_STATE</code>.
98 ***/
99 public POP3()
100 {
101 setDefaultPort(DEFAULT_PORT);
102 __commandBuffer = new StringBuffer();
103 __popState = DISCONNECTED_STATE;
104 _reader = null;
105 __writer = null;
106 _replyLines = new Vector<String>();
107 _commandSupport_ = new ProtocolCommandSupport(this);
108 }
109
110 private void __getReply() throws IOException
111 {
112 String line;
113
114 _replyLines.setSize(0);
115 line = _reader.readLine();
116
117 if (line == null)
118 throw new EOFException("Connection closed without indication.");
119
120 if (line.startsWith(_OK))
121 _replyCode = POP3Reply.OK;
122 else if (line.startsWith(_ERROR))
123 _replyCode = POP3Reply.ERROR;
124 else
125 throw new
126 MalformedServerReplyException(
127 "Received invalid POP3 protocol response from server.");
128
129 _replyLines.addElement(line);
130 _lastReplyLine = line;
131
132 if (_commandSupport_.getListenerCount() > 0)
133 _commandSupport_.fireReplyReceived(_replyCode, getReplyString());
134 }
135
136
137 /***
138 * Performs connection initialization and sets state to
139 * <code> AUTHORIZATION_STATE </code>.
140 ***/
141 @Override
142 protected void _connectAction_() throws IOException
143 {
144 super._connectAction_();
145 _reader =
146 new BufferedReader(new InputStreamReader(_input_,
147 __DEFAULT_ENCODING));
148 __writer =
149 new BufferedWriter(new OutputStreamWriter(_output_,
150 __DEFAULT_ENCODING));
151 __getReply();
152 setState(AUTHORIZATION_STATE);
153 }
154
155
156 /***
157 * Adds a ProtocolCommandListener. Delegates this task to
158 * {@link #_commandSupport_ _commandSupport_ }.
159 * <p>
160 * @param listener The ProtocolCommandListener to add.
161 ***/
162 public void addProtocolCommandListener(ProtocolCommandListener listener)
163 {
164 _commandSupport_.addProtocolCommandListener(listener);
165 }
166
167 /***
168 * Removes a ProtocolCommandListener. Delegates this task to
169 * {@link #_commandSupport_ _commandSupport_ }.
170 * <p>
171 * @param listener The ProtocolCommandListener to remove.
172 ***/
173 public void removeProtocolCommandistener(ProtocolCommandListener listener)
174 {
175 _commandSupport_.removeProtocolCommandListener(listener);
176 }
177
178
179 /***
180 * Sets POP3 client state. This must be one of the
181 * <code>_STATE</code> constants.
182 * <p>
183 * @param state The new state.
184 ***/
185 public void setState(int state)
186 {
187 __popState = state;
188 }
189
190
191 /***
192 * Returns the current POP3 client state.
193 * <p>
194 * @return The current POP3 client state.
195 ***/
196 public int getState()
197 {
198 return __popState;
199 }
200
201
202 /***
203 * Retrieves the additional lines of a multi-line server reply.
204 ***/
205 public void getAdditionalReply() throws IOException
206 {
207 String line;
208
209 line = _reader.readLine();
210 while (line != null)
211 {
212 _replyLines.addElement(line);
213 if (line.equals("."))
214 break;
215 line = _reader.readLine();
216 }
217 }
218
219
220 /***
221 * Disconnects the client from the server, and sets the state to
222 * <code> DISCONNECTED_STATE </code>. The reply text information
223 * from the last issued command is voided to allow garbage collection
224 * of the memory used to store that information.
225 * <p>
226 * @exception IOException If there is an error in disconnecting.
227 ***/
228 @Override
229 public void disconnect() throws IOException
230 {
231 super.disconnect();
232 _reader = null;
233 __writer = null;
234 _lastReplyLine = null;
235 _replyLines.setSize(0);
236 setState(DISCONNECTED_STATE);
237 }
238
239
240 /***
241 * Sends a command an arguments to the server and returns the reply code.
242 * <p>
243 * @param command The POP3 command to send.
244 * @param args The command arguments.
245 * @return The server reply code (either POP3Reply.OK or POP3Reply.ERROR).
246 ***/
247 public int sendCommand(String command, String args) throws IOException
248 {
249 String message;
250
251 __commandBuffer.setLength(0);
252 __commandBuffer.append(command);
253
254 if (args != null)
255 {
256 __commandBuffer.append(' ');
257 __commandBuffer.append(args);
258 }
259 __commandBuffer.append(SocketClient.NETASCII_EOL);
260
261 __writer.write(message = __commandBuffer.toString());
262 __writer.flush();
263
264 if (_commandSupport_.getListenerCount() > 0)
265 _commandSupport_.fireCommandSent(command, message);
266
267 __getReply();
268 return _replyCode;
269 }
270
271 /***
272 * Sends a command with no arguments to the server and returns the
273 * reply code.
274 * <p>
275 * @param command The POP3 command to send.
276 * @return The server reply code (either POP3Reply.OK or POP3Reply.ERROR).
277 ***/
278 public int sendCommand(String command) throws IOException
279 {
280 return sendCommand(command, null);
281 }
282
283 /***
284 * Sends a command an arguments to the server and returns the reply code.
285 * <p>
286 * @param command The POP3 command to send
287 * (one of the POP3Command constants).
288 * @param args The command arguments.
289 * @return The server reply code (either POP3Reply.OK or POP3Reply.ERROR).
290 ***/
291 public int sendCommand(int command, String args) throws IOException
292 {
293 return sendCommand(POP3Command._commands[command], args);
294 }
295
296 /***
297 * Sends a command with no arguments to the server and returns the
298 * reply code.
299 * <p>
300 * @param command The POP3 command to send
301 * (one of the POP3Command constants).
302 * @return The server reply code (either POP3Reply.OK or POP3Reply.ERROR).
303 ***/
304 public int sendCommand(int command) throws IOException
305 {
306 return sendCommand(POP3Command._commands[command], null);
307 }
308
309
310 /***
311 * Returns an array of lines received as a reply to the last command
312 * sent to the server. The lines have end of lines truncated. If
313 * the reply is a single line, but its format ndicates it should be
314 * a multiline reply, then you must call
315 * {@link #getAdditionalReply getAdditionalReply() } to
316 * fetch the rest of the reply, and then call <code>getReplyStrings</code>
317 * again. You only have to worry about this if you are implementing
318 * your own client using the {@link #sendCommand sendCommand } methods.
319 * <p>
320 * @return The last server response.
321 ***/
322 public String[] getReplyStrings()
323 {
324 String[] lines;
325 lines = new String[_replyLines.size()];
326 _replyLines.copyInto(lines);
327 return lines;
328 }
329
330 /***
331 * Returns the reply to the last command sent to the server.
332 * The value is a single string containing all the reply lines including
333 * newlines. If the reply is a single line, but its format ndicates it
334 * should be a multiline reply, then you must call
335 * {@link #getAdditionalReply getAdditionalReply() } to
336 * fetch the rest of the reply, and then call <code>getReplyString</code>
337 * again. You only have to worry about this if you are implementing
338 * your own client using the {@link #sendCommand sendCommand } methods.
339 * <p>
340 * @return The last server response.
341 ***/
342 public String getReplyString()
343 {
344 Enumeration<String> en;
345 StringBuffer buffer = new StringBuffer(256);
346
347 en = _replyLines.elements();
348 while (en.hasMoreElements())
349 {
350 buffer.append(en.nextElement());
351 buffer.append(SocketClient.NETASCII_EOL);
352 }
353
354 return buffer.toString();
355 }
356
357 }
358