| 1 | package be.nikiroo.jvcard.remote; |
| 2 | |
| 3 | import java.io.BufferedReader; |
| 4 | import java.io.Closeable; |
| 5 | import java.io.IOException; |
| 6 | import java.io.InputStreamReader; |
| 7 | import java.io.PrintWriter; |
| 8 | import java.net.InetAddress; |
| 9 | import java.net.Socket; |
| 10 | import java.util.Arrays; |
| 11 | import java.util.LinkedList; |
| 12 | import java.util.List; |
| 13 | |
| 14 | /** |
| 15 | * A client or server connection, that will allow you to connect to, send and |
| 16 | * receive data to/from a jVCard remote server. |
| 17 | * |
| 18 | * |
| 19 | * |
| 20 | * @author niki |
| 21 | */ |
| 22 | public class SimpleSocket { |
| 23 | /** |
| 24 | * An {@link Appendable} that can be used to send data over a |
| 25 | * {@link SimpleSocket}. You must close it to send the end of block element. |
| 26 | * |
| 27 | * @author niki |
| 28 | * |
| 29 | */ |
| 30 | public class BlockAppendable implements Appendable, Closeable { |
| 31 | private SimpleSocket ss; |
| 32 | |
| 33 | /** |
| 34 | * Create a new {@link BlockAppendable} for the given |
| 35 | * {@link SimpleSocket}. |
| 36 | * |
| 37 | * @param ss |
| 38 | * the {@link SimpleSocket} |
| 39 | */ |
| 40 | public BlockAppendable(SimpleSocket ss) { |
| 41 | this.ss = ss; |
| 42 | } |
| 43 | |
| 44 | @Override |
| 45 | public Appendable append(CharSequence csq) throws IOException { |
| 46 | ss.send(csq); |
| 47 | return this; |
| 48 | } |
| 49 | |
| 50 | @Override |
| 51 | public Appendable append(char c) throws IOException { |
| 52 | ss.send("" + c); |
| 53 | return this; |
| 54 | } |
| 55 | |
| 56 | @Override |
| 57 | public Appendable append(CharSequence csq, int start, int end) |
| 58 | throws IOException { |
| 59 | ss.send(csq.subSequence(start, end)); |
| 60 | return this; |
| 61 | } |
| 62 | |
| 63 | @Override |
| 64 | public void close() throws IOException { |
| 65 | ss.sendBlock(); |
| 66 | } |
| 67 | |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * The current version of the network protocol. |
| 72 | */ |
| 73 | static public final int CURRENT_VERSION = 1; |
| 74 | |
| 75 | /** |
| 76 | * The end of block marker. |
| 77 | * |
| 78 | * An end of block marker needs to be on a line on itself to be valid, and |
| 79 | * will denote the end of a block of data. |
| 80 | */ |
| 81 | static private String EOB = "."; |
| 82 | |
| 83 | private Socket s; |
| 84 | private PrintWriter out; |
| 85 | private BufferedReader in; |
| 86 | private int version; // version of the OTHER end, not this one (this one is |
| 87 | // CURRENT_VERSION obviously) |
| 88 | |
| 89 | private String label; // can be used for debugging |
| 90 | |
| 91 | /** |
| 92 | * Create a new {@link SimpleSocket} with the given {@link Socket}. |
| 93 | * |
| 94 | * @param s |
| 95 | * the {@link Socket} |
| 96 | */ |
| 97 | public SimpleSocket(Socket s, String label) { |
| 98 | this.s = s; |
| 99 | this.label = label; |
| 100 | } |
| 101 | |
| 102 | /** |
| 103 | * Return the label of this {@link SimpleSocket}. This is mainly used for |
| 104 | * debugging purposes or user display if any. It is optional. |
| 105 | * |
| 106 | * @return the label |
| 107 | */ |
| 108 | public String getLabel() { |
| 109 | if (label == null) |
| 110 | return "[no name]"; |
| 111 | return label; |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Open the {@link SimpleSocket} for reading/writing and negotiates the |
| 116 | * version. |
| 117 | * |
| 118 | * Note that you <b>MUST</b> call {@link SimpleSocket#close()} when you are |
| 119 | * done to release the acquired resources. |
| 120 | * |
| 121 | * @param client |
| 122 | * TRUE for clients, FALSE for servers (server speaks first) |
| 123 | * |
| 124 | * @throws IOException |
| 125 | * in case of IO error |
| 126 | */ |
| 127 | public void open(boolean client) throws IOException { |
| 128 | out = new PrintWriter(s.getOutputStream(), false); |
| 129 | in = new BufferedReader(new InputStreamReader(s.getInputStream())); |
| 130 | |
| 131 | if (client) { |
| 132 | version = new CommandInstance(receiveLine(), -1).getVersion(); |
| 133 | sendLine(new CommandInstance(Command.VERSION, CURRENT_VERSION) |
| 134 | .toString()); |
| 135 | } else { |
| 136 | send(new CommandInstance(Command.VERSION, CURRENT_VERSION) |
| 137 | .toString()); |
| 138 | // TODO: i18n |
| 139 | send("[Some help info here]"); |
| 140 | send("you need to reply with your VERSION + end of block"); |
| 141 | send("please send HELP in a full block or help"); |
| 142 | sendBlock(); |
| 143 | version = new CommandInstance(receiveLine(), -1).getVersion(); |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * Close the connection and release acquired resources. |
| 149 | * |
| 150 | * @return TRUE if everything was closed properly, FALSE if the connection |
| 151 | * was broken (in all cases, resources are released) |
| 152 | */ |
| 153 | public boolean close() { |
| 154 | boolean broken = false; |
| 155 | |
| 156 | try { |
| 157 | sendBlock(); |
| 158 | broken = out.checkError(); |
| 159 | } catch (IOException e) { |
| 160 | broken = true; |
| 161 | } |
| 162 | |
| 163 | try { |
| 164 | s.close(); |
| 165 | } catch (IOException e) { |
| 166 | e.printStackTrace(); |
| 167 | broken = true; |
| 168 | try { |
| 169 | in.close(); |
| 170 | } catch (IOException ee) { |
| 171 | } |
| 172 | out.close(); |
| 173 | } |
| 174 | |
| 175 | s = null; |
| 176 | in = null; |
| 177 | out = null; |
| 178 | |
| 179 | return !broken; |
| 180 | } |
| 181 | |
| 182 | /** |
| 183 | * Sends lines to the remote server. Do <b>NOT</b> sends the end-of-block |
| 184 | * marker. |
| 185 | * |
| 186 | * @param data |
| 187 | * the data to send |
| 188 | * |
| 189 | * @throws IOException |
| 190 | * in case of IO error |
| 191 | */ |
| 192 | protected void send(CharSequence data) throws IOException { |
| 193 | if (data != null) { |
| 194 | out.append(data); |
| 195 | } |
| 196 | |
| 197 | out.append("\n"); |
| 198 | |
| 199 | if (out.checkError()) |
| 200 | throw new IOException(); |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * Sends an end-of-block marker to the remote server. |
| 205 | * |
| 206 | * @throws IOException |
| 207 | * in case of IO error |
| 208 | */ |
| 209 | public void sendBlock() throws IOException { |
| 210 | sendBlock((List<String>) null); |
| 211 | } |
| 212 | |
| 213 | /** |
| 214 | * Sends commands to the remote server, then sends an end-of-block marker. |
| 215 | * |
| 216 | * @param data |
| 217 | * the data to send |
| 218 | * |
| 219 | * @throws IOException |
| 220 | * in case of IO error |
| 221 | */ |
| 222 | public void sendLine(String data) throws IOException { |
| 223 | sendBlock(Arrays.asList(new String[] { data })); |
| 224 | } |
| 225 | |
| 226 | /** |
| 227 | * Sends commands to the remote server, then sends an end-of-block marker. |
| 228 | * |
| 229 | * @param data |
| 230 | * the data to send |
| 231 | * |
| 232 | * @throws IOException |
| 233 | * in case of IO error |
| 234 | */ |
| 235 | public void sendBlock(List<String> data) throws IOException { |
| 236 | if (data != null) { |
| 237 | for (String dataLine : data) { |
| 238 | send(dataLine); |
| 239 | } |
| 240 | } |
| 241 | |
| 242 | send(EOB); |
| 243 | } |
| 244 | |
| 245 | /** |
| 246 | * Sends commands to the remote server, then sends an end-of-block marker. |
| 247 | * |
| 248 | * @param command |
| 249 | * the {@link Command} to send |
| 250 | * |
| 251 | * @throws IOException |
| 252 | * in case of IO error |
| 253 | */ |
| 254 | public void sendCommand(Command command) throws IOException { |
| 255 | sendCommand(command, null); |
| 256 | } |
| 257 | |
| 258 | /** |
| 259 | * Sends commands to the remote server, then sends an end-of-block marker. |
| 260 | * |
| 261 | * @param command |
| 262 | * the data to send |
| 263 | * |
| 264 | * @param param |
| 265 | * the parameter for this command if any |
| 266 | * |
| 267 | * @throws IOException |
| 268 | * in case of IO error |
| 269 | */ |
| 270 | public void sendCommand(Command command, String param) throws IOException { |
| 271 | sendLine(new CommandInstance(command, param, CURRENT_VERSION) |
| 272 | .toString()); |
| 273 | } |
| 274 | |
| 275 | /** |
| 276 | * Create a new {@link Appendable} that can be used to send data on this |
| 277 | * {@link SimpleSocket}. When you are done, just call |
| 278 | * {@link BlockAppendable#close()}. |
| 279 | * |
| 280 | * @return the {@link Appendable} |
| 281 | */ |
| 282 | public BlockAppendable createBlockAppendable() { |
| 283 | return new BlockAppendable(this); |
| 284 | } |
| 285 | |
| 286 | /** |
| 287 | * Read a line from the remote server. |
| 288 | * |
| 289 | * Do <b>NOT</b> read until the end-of-block marker, and can return said |
| 290 | * block without conversion. |
| 291 | * |
| 292 | * @return the read line |
| 293 | * |
| 294 | * @throws IOException |
| 295 | * in case of IO error |
| 296 | */ |
| 297 | protected String receive() throws IOException { |
| 298 | String line = in.readLine(); |
| 299 | return line; |
| 300 | } |
| 301 | |
| 302 | /** |
| 303 | * Read lines from the remote server until the end-of-block ("\0\n") marker |
| 304 | * is detected. |
| 305 | * |
| 306 | * @return the read lines without the end marker, or NULL if nothing more to |
| 307 | * read |
| 308 | * |
| 309 | * @throws IOException |
| 310 | * in case of IO error |
| 311 | */ |
| 312 | public List<String> receiveBlock() throws IOException { |
| 313 | List<String> result = new LinkedList<String>(); |
| 314 | |
| 315 | String line = receive(); |
| 316 | for (; line != null && !line.equals(EOB); line = receive()) { |
| 317 | result.add(line); |
| 318 | } |
| 319 | |
| 320 | if (line == null) |
| 321 | return null; |
| 322 | |
| 323 | return result; |
| 324 | } |
| 325 | |
| 326 | /** |
| 327 | * Read a line from the remote server then read until the next end-of-block |
| 328 | * marker. |
| 329 | * |
| 330 | * @return the parsed line, or NULL if nothing more to read |
| 331 | * |
| 332 | * @throws IOException |
| 333 | * in case of IO error |
| 334 | */ |
| 335 | public String receiveLine() throws IOException { |
| 336 | List<String> lines = receiveBlock(); |
| 337 | |
| 338 | if (lines.size() > 0) |
| 339 | return lines.get(0); |
| 340 | |
| 341 | return null; |
| 342 | } |
| 343 | |
| 344 | /** |
| 345 | * Read a line from the remote server and convert it to a |
| 346 | * {@link CommandInstance}, then read until the next end-of-block marker. |
| 347 | * |
| 348 | * @return the parsed {@link CommandInstance} |
| 349 | * |
| 350 | * @throws IOException |
| 351 | * in case of IO error |
| 352 | */ |
| 353 | public CommandInstance receiveCommand() throws IOException { |
| 354 | String line = receive(); |
| 355 | CommandInstance cmd = new CommandInstance(line, version); |
| 356 | receiveBlock(); |
| 357 | return cmd; |
| 358 | } |
| 359 | |
| 360 | @Override |
| 361 | public String toString() { |
| 362 | String source = "[not connected]"; |
| 363 | InetAddress iadr = s.getInetAddress(); |
| 364 | if (iadr != null) |
| 365 | source = iadr.getHostName(); |
| 366 | |
| 367 | return getLabel() + " (" + source + ")"; |
| 368 | } |
| 369 | } |