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