4 * Copyright 2015 TJ <hacker@iam.tj>.
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 package uk.ac.ntu.n0521366.wsyd.libs.net;
26 import java.text.MessageFormat;
27 import java.net.InetSocketAddress;
28 import java.net.SocketException;
29 import java.util.concurrent.ConcurrentLinkedQueue;
30 import java.util.concurrent.ConcurrentHashMap;
31 import java.util.ArrayList;
32 import java.util.List;
33 import java.util.logging.Logger;
34 import java.util.logging.Level;
35 import javax.swing.SwingWorker;
38 * Abstract dual-use multithreading network server that can be used stand-alone
39 * or in a Swing GUI application as a background worker thread.
41 * Concrete classes are required to implement the Socket-specific functionality.
43 * The arguments to the Generics superclass SwingWorker<T, V> are:
45 * < return-TYPE-of doInBackground(), publish(parameter-TYPE) >
47 * Here doInBackground() returns an Integer connection counter and publish() takes
48 * a NetworkMessage type.
50 * Server sockets block in the operating system kernel waiting
51 * for connections or incoming packets.
53 * SwingWorker objects avoid using the GUI event dispatcher thread. Without that the
54 * user interface could be unresponsive for considerable periods whilst server
55 * sockets wait for incoming connections via the blocking in
56 * ServerSocket.accept() (TCP) or DatagramSocket.receive() (UDP) method.
58 * This design combines the multithreading support of the java.lang.Runnable
59 * interface with the javax.swing.SwingWorker inheritance so that this single class
60 * can be used in non-GUI daemon services and GUI applications, avoiding the need
61 * to write the same server code in more than one class.
63 * The server registers NetworkMessageEventListener objects and notifies them
64 * when a new NetworkMessage has been received.
66 * @see javax.swing.SwingWorker
68 * @author TJ <hacker@iam.tj>
70 public abstract class NetworkServerAbstract extends SwingWorker<Integer, NetworkMessage> implements NetworkMessageEventGenerator {
73 * Single Logger for the class used by all object instances.
75 * Can be instantiated once by objects of any sub-class.
77 @SuppressWarnings("NonConstantLogger")
78 protected static Logger LOGGER = null;
81 * Inject simulated received NetworkMessages.
83 * A helpful tool for debugging.
85 protected boolean _simulate = false;
88 * Count of packets or connections received.
93 * Service name for this server instance.
95 * E.g. "ServerSocial", "ServerChat", "ServerControl", "ClientControl", "ClientChat", "ServerLog"
100 * Socket parameters for this server.
102 WSYD_SocketAddress _socketAddress;
104 protected ServiceAddressMap _serviceToHostMap;
106 * Thread safe First In, First Out Queue of NetworkMessage objects waiting to be sent.
108 * Allows the Owner Thread to submit new messages for sending that the Worker Thread
111 protected ConcurrentLinkedQueue<NetworkMessage> _sendMessageQueue = new ConcurrentLinkedQueue<>();
114 * Wrapper for filtering NetworkMessageEvents based on the message intent
116 public class NetworkMessageEventListenerWithIntent {
118 NetworkMessageEventListener _listener;
120 public NetworkMessageEventListenerWithIntent(NetworkMessageEventListener listener, String intent) {
122 _listener = listener;
125 protected ArrayList<NetworkMessageEventListenerWithIntent> _NetworkMessageEventListeners = new ArrayList<>();
129 * @param level message importance
130 * @param title source identifier
131 * @param formatter parameter Formatter for log message
132 * @param parameters variable length list of replaceable parameters for formatter
134 protected static void log(Level level, String title, String formatter, ArrayList<String> parameters) {
137 // formatter = "{" + Integer.toString(parameters.size()) + "}: " + formatter;
138 // parameters.add(title);
139 LOGGER.logp(level, title, null, MessageFormat.format(formatter, parameters.toArray()));
143 * @param level message importance
144 * @param title source identifier
145 * @param message the log entry
147 protected static void log(Level level, String title, String message) {
150 LOGGER.logp(level, title, null, message);
154 * Set the log level for the server
155 * @param level a new log level
156 * @return the old log level
158 public Level setLogLevel(Level level) {
159 Level result = Level.OFF;
160 if (LOGGER != null) {
161 Level temp = LOGGER.getLevel();
162 LOGGER.setLevel(level);
169 * Default constructor.
171 NetworkServerAbstract() {
172 this._connectionCount = 0;
174 this._socketAddress = null;
175 this._serviceToHostMap = null;
179 * Construct the server with a Logger.
181 * No socket is opened.
183 * @param socketAddress The socket to listen on
184 * @param title source identifier for use in log messages and sent NetworkMessage objects
185 * @param serviceToHostMap the map object used for host <> InetSocketAddress lookups
186 * @param logger An instance of Logger to be used by all objects of this class
188 public NetworkServerAbstract(WSYD_SocketAddress socketAddress, String title, ServiceAddressMap serviceToHostMap, Logger logger) {
189 this._connectionCount = 0;
191 this._socketAddress = socketAddress;
192 this._serviceToHostMap = serviceToHostMap;
193 if (LOGGER == null) // do not replace existing logger reference
198 * Construct the server without a Logger.
200 * No socket is opened.
202 * @param socketAddress The socket to listen on
203 * @param title source identifier for use in log messages and sent NetworkMessage objects
204 * @param serviceToHostMap the map object used for host <> InetSocketAddress lookups
206 public NetworkServerAbstract(WSYD_SocketAddress socketAddress, String title, ServiceAddressMap serviceToHostMap) {
207 this(socketAddress, title, serviceToHostMap, null);
211 * Enable or disable simulated received packet injection.
213 * @param simulate true to simulate received messages
215 public void setSimulate(boolean simulate) {
216 this._simulate = simulate;
220 * Get the simulation state.
222 * @return true if simulation is enabled.
224 public boolean getSimulate() {
225 return this._simulate;
229 /* XXX: The following Methods execute on the background Worker Thread */
232 * The primary SwingWorker method, started on the Worker Thread when the Owner
233 * Thread calls execute().
235 * Loops until isCancelled() == true. Within the loop calls serverListen() to
236 * allow reception of one packet or connection and if so counts it.
237 * Then it checks if there are any messages to be sent out and if so calls
240 * @return the number of connections accepted
243 public Integer doInBackground() {
244 ArrayList<String> logMessages = new ArrayList<>();
246 logMessages.add(_socketAddress.toString());
247 log(Level.INFO, _title, "Opening socket {0}", logMessages);
250 catch(SocketException e) {
252 logMessages.add(_socketAddress.getAddress().toString());
253 logMessages.add(Integer.toString(_socketAddress.getPort()));
254 logMessages.add(_socketAddress.getProtocol().toString());
255 log(Level.SEVERE, _title, "{0}: Unable to open socket on {1}:{2} {3}", logMessages);
258 // unless cancelled keep waiting for new packets or connections
259 while (!this.isCancelled()) {
260 if (this.serverListen())
261 this._connectionCount++;
263 // send a queued message
264 NetworkMessage temp = this.dequeueMessage();
266 if (!this.serverSend(temp)) {
268 logMessages.add(temp.getSender());
269 logMessages.add(temp.getTarget());
270 log(Level.WARNING, _title, "Unable to send message from {0} to {1}", logMessages);
277 logMessages.add(_socketAddress.toString());
278 log(Level.INFO, _title, "Closing socket {0}", logMessages);
281 catch(SocketException e) {
283 logMessages.add(_socketAddress.getAddress().toString());
284 logMessages.add(Integer.toString(_socketAddress.getPort()));
285 logMessages.add(_socketAddress.getProtocol().toString());
286 log(Level.SEVERE, _title, "{0}: Unable to close socket on {1}:{2} {3}", logMessages);
289 return this._connectionCount;
294 * Open the socket ready for accepting data or connections.
296 * It should also set a reasonable socket timeout with a call to setSoTimeout()
298 * @see java.net.ServerSocket#setSoTimeout
299 * @see java.net.DatagramSocket#setSoTimeout
300 * @throws SocketException
302 public abstract void serverOpen() throws SocketException;
307 * @throws SocketException
309 public abstract void serverClose() throws SocketException;
312 * Send an unsolicited message to a remote service.
314 * This method is called by the main worker loop if there is a message to
317 * @param message must have its _serviceTarget parameter set
318 * @return true if the message was sent
320 protected abstract boolean serverSend(NetworkMessage message);
323 * Accept packet or connection from remote hosts.
325 * This method must wait for a single incoming connection or packet, process it,
326 * and then publish() it for consumption by process().
328 * It must add newly seen remote service names to _serviceToHostMap so that
329 * methods on the Owner Thread can discover the destination service titles
330 * they can use in new NetworkMessage submissions.
332 * @return true if the server should continue listening
334 public abstract boolean serverListen();
337 * Removes a message from the queue of pending messages.
339 * This method is called on the Worker Thread by the doInBackground() main loop.
341 * @return a message to be sent
343 protected NetworkMessage dequeueMessage() {
344 return this._sendMessageQueue.poll();
347 /* XXX: Methods below here all execute on the GUI Event Dispatch Thread */
351 * Fetch messages received by the server.
353 * For delivery to event listeners; usually Swing GUI components. This method will run on the
354 * Owner Thread so must complete quickly it that is the GUI Event Dispatch Thread.
356 * @param list messages received and queued
359 protected void process(List<NetworkMessage> list) {
360 for (NetworkMessage message: list) {
361 fireNetworkMessageEvent(message);
366 * Clean up after doInBackground() has returned.
368 * This method will run on the GUI Event Dispatch Thread so must complete quickly.
371 protected abstract void done();
374 * Adds a message to the queue of pending messages.
376 * This method will usually be called from the Owner Thread.
378 * @param message to be sent
379 * @return true if the message was added to the queue
380 * @throws IllegalArgumentException if the target does not exist in the serviceToHost mapping
382 public boolean queueMessage(NetworkMessage message) throws IllegalArgumentException {
383 boolean result = false;
384 if (message != null) {
385 // ensure the target is set and is a valid service
386 String target = message.getTarget();
388 throw new IllegalArgumentException("target cannot be null");
389 if(!_serviceToHostMap.isServiceValid(target))
390 throw new IllegalArgumentException("target service does not exist: " + target);
393 try { // make a deep clone of the message
394 temp = NetworkMessage.clone(message);
395 result = this._sendMessageQueue.add(temp);
396 } catch (CloneNotSupportedException e) {
397 // TODO: queueMessage() log CloneNotSupportedException
405 * Add a NetworkMessageEvent listener.
407 * Listens to all intents.
412 public synchronized void addNetworkMessageEventListener(NetworkMessageEventListener listener) {
413 _NetworkMessageEventListeners.add(new NetworkMessageEventListenerWithIntent(listener, null));
417 * Add a filtered NetworkMessageEvent listener.
419 * Filters on the intent of the NetworkMessage.
421 * @param intent null to listen to all intents, otherwise the intent to listen for
424 public synchronized void addNetworkMessageEventListener(NetworkMessageEventListener listener, String intent) {
425 _NetworkMessageEventListeners.add(new NetworkMessageEventListenerWithIntent(listener, intent));
429 * Remove a NetworkMessageEvent listener.
434 public synchronized void removeNetworkMessageEventListener(NetworkMessageEventListener listener) {
435 for (NetworkMessageEventListenerWithIntent intentListener : _NetworkMessageEventListeners)
436 if (intentListener._listener == listener)
437 _NetworkMessageEventListeners.remove(intentListener);
441 * Send a NetworkMessageEvent to all listeners.
443 * Only sends the message to listeners registered for the same intent, or for all messages.
445 * @param message the NetworkMessage to send
447 private synchronized void fireNetworkMessageEvent(NetworkMessage message) {
448 NetworkMessageEvent event = new NetworkMessageEvent(this, message);
449 for (NetworkMessageEventListenerWithIntent intentListener : _NetworkMessageEventListeners) {
450 if (intentListener._intent.equals(message._intent) || intentListener._intent == null)
451 intentListener._listener.NetworkMessageReceived(event);