| 1 | package be.nikiroo.utils.serial.server; |
| 2 | |
| 3 | import java.io.BufferedReader; |
| 4 | import java.io.IOException; |
| 5 | import java.io.InputStreamReader; |
| 6 | import java.io.OutputStreamWriter; |
| 7 | import java.net.Socket; |
| 8 | |
| 9 | import javax.net.ssl.SSLException; |
| 10 | |
| 11 | import be.nikiroo.utils.Version; |
| 12 | import be.nikiroo.utils.serial.Exporter; |
| 13 | import be.nikiroo.utils.serial.Importer; |
| 14 | |
| 15 | /** |
| 16 | * Base class used for the client/server basic handling. |
| 17 | * <p> |
| 18 | * It represents a single action: a client is expected to only execute one |
| 19 | * action, while a server is expected to execute one action for each client |
| 20 | * action. |
| 21 | * |
| 22 | * @author niki |
| 23 | */ |
| 24 | abstract class ConnectAction { |
| 25 | private Socket s; |
| 26 | private boolean server; |
| 27 | private Version version; |
| 28 | private Version clientVersion; |
| 29 | |
| 30 | private Object lock = new Object(); |
| 31 | private BufferedReader in; |
| 32 | private OutputStreamWriter out; |
| 33 | private boolean contentToSend; |
| 34 | |
| 35 | private long bytesReceived; |
| 36 | private long bytesSent; |
| 37 | |
| 38 | /** |
| 39 | * Method that will be called when an action is performed on either the |
| 40 | * client or server this {@link ConnectAction} represent. |
| 41 | * |
| 42 | * @param version |
| 43 | * the counter part version |
| 44 | * |
| 45 | * @throws Exception |
| 46 | * in case of I/O error |
| 47 | */ |
| 48 | abstract protected void action(Version version) throws Exception; |
| 49 | |
| 50 | /** |
| 51 | * Method called when we negotiate the version with the client. |
| 52 | * <p> |
| 53 | * Thus, it is only called on the server. |
| 54 | * <p> |
| 55 | * Will return the actual server version by default. |
| 56 | * |
| 57 | * @param clientVersion |
| 58 | * the client version |
| 59 | * |
| 60 | * @return the version to send to the client |
| 61 | */ |
| 62 | abstract protected Version negotiateVersion(Version clientVersion); |
| 63 | |
| 64 | /** |
| 65 | * Handler called when an unexpected error occurs in the code. |
| 66 | * |
| 67 | * @param e |
| 68 | * the exception that occurred |
| 69 | */ |
| 70 | abstract protected void onError(Exception e); |
| 71 | |
| 72 | /** |
| 73 | * Create a new {@link ConnectAction}. |
| 74 | * |
| 75 | * @param s |
| 76 | * the socket to bind to |
| 77 | * @param server |
| 78 | * TRUE for a server action, FALSE for a client action (will |
| 79 | * impact the process) |
| 80 | * @param version |
| 81 | * the version of this client-or-server |
| 82 | */ |
| 83 | protected ConnectAction(Socket s, boolean server, Version version) { |
| 84 | this.s = s; |
| 85 | this.server = server; |
| 86 | |
| 87 | if (version == null) { |
| 88 | this.version = new Version(); |
| 89 | } else { |
| 90 | this.version = version; |
| 91 | } |
| 92 | |
| 93 | clientVersion = new Version(); |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * The version of this client-or-server. |
| 98 | * |
| 99 | * @return the version |
| 100 | */ |
| 101 | public Version getVersion() { |
| 102 | return version; |
| 103 | } |
| 104 | |
| 105 | /** |
| 106 | * The total amount of bytes received. |
| 107 | * |
| 108 | * @return the amount of bytes received |
| 109 | */ |
| 110 | public long getBytesReceived() { |
| 111 | return bytesReceived; |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * The total amount of bytes sent. |
| 116 | * |
| 117 | * @return the amount of bytes sent |
| 118 | */ |
| 119 | public long getBytesSent() { |
| 120 | return bytesSent; |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * Actually start the process (this is synchronous). |
| 125 | */ |
| 126 | public void connect() { |
| 127 | try { |
| 128 | in = new BufferedReader(new InputStreamReader(s.getInputStream(), |
| 129 | "UTF-8")); |
| 130 | try { |
| 131 | out = new OutputStreamWriter(s.getOutputStream(), "UTF-8"); |
| 132 | try { |
| 133 | if (server) { |
| 134 | String line = in.readLine(); |
| 135 | if (line != null && line.startsWith("VERSION ")) { |
| 136 | // "VERSION client-version" (VERSION 1.0.0) |
| 137 | Version clientVersion = new Version( |
| 138 | line.substring("VERSION ".length())); |
| 139 | this.clientVersion = clientVersion; |
| 140 | Version v = negotiateVersion(clientVersion); |
| 141 | if (v == null) { |
| 142 | v = new Version(); |
| 143 | } |
| 144 | |
| 145 | sendString("VERSION " + v.toString()); |
| 146 | } |
| 147 | |
| 148 | action(clientVersion); |
| 149 | } else { |
| 150 | String v = sendString("VERSION " + version.toString()); |
| 151 | if (v != null && v.startsWith("VERSION ")) { |
| 152 | v = v.substring("VERSION ".length()); |
| 153 | } |
| 154 | |
| 155 | action(new Version(v)); |
| 156 | } |
| 157 | } finally { |
| 158 | out.close(); |
| 159 | out = null; |
| 160 | } |
| 161 | } finally { |
| 162 | in.close(); |
| 163 | in = null; |
| 164 | } |
| 165 | } catch (Exception e) { |
| 166 | if (e instanceof SSLException) { |
| 167 | String ciphers = ""; |
| 168 | for (String cipher : Server.getAnonCiphers()) { |
| 169 | if (!ciphers.isEmpty()) { |
| 170 | ciphers += ", "; |
| 171 | } |
| 172 | ciphers += cipher; |
| 173 | } |
| 174 | |
| 175 | e = new SSLException("SSL error (available SSL ciphers: " |
| 176 | + ciphers + ")", e); |
| 177 | } |
| 178 | |
| 179 | onError(e); |
| 180 | } finally { |
| 181 | try { |
| 182 | s.close(); |
| 183 | } catch (Exception e) { |
| 184 | onError(e); |
| 185 | } |
| 186 | } |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * Serialise and send the given object to the counter part (and, only for |
| 191 | * client, return the deserialised answer -- the server will always receive |
| 192 | * NULL). |
| 193 | * |
| 194 | * @param data |
| 195 | * the data to send |
| 196 | * |
| 197 | * @return the answer (which can be NULL) if this action is a client, always |
| 198 | * NULL if it is a server |
| 199 | * |
| 200 | * @throws IOException |
| 201 | * in case of I/O error |
| 202 | * @throws NoSuchFieldException |
| 203 | * if the serialised data contains information about a field |
| 204 | * which does actually not exist in the class we know of |
| 205 | * @throws NoSuchMethodException |
| 206 | * if a class described in the serialised data cannot be created |
| 207 | * because it is not compatible with this code |
| 208 | * @throws ClassNotFoundException |
| 209 | * if a class described in the serialised data cannot be found |
| 210 | */ |
| 211 | protected Object sendObject(Object data) throws IOException, |
| 212 | NoSuchFieldException, NoSuchMethodException, ClassNotFoundException { |
| 213 | synchronized (lock) { |
| 214 | String rep = sendString(new Exporter().append(data).toString(true, |
| 215 | true)); |
| 216 | if (rep != null) { |
| 217 | return new Importer().read(rep).getValue(); |
| 218 | } |
| 219 | |
| 220 | return null; |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * Reserved for the server: flush the data to the client and retrieve its |
| 226 | * answer. |
| 227 | * <p> |
| 228 | * Also used internally for the client (only do something if there is |
| 229 | * contentToSend). |
| 230 | * <p> |
| 231 | * Will only flush the data if there is contentToSend. |
| 232 | * |
| 233 | * @return the deserialised answer (which can actually be NULL) |
| 234 | * |
| 235 | * @throws IOException |
| 236 | * in case of I/O error |
| 237 | * @throws NoSuchFieldException |
| 238 | * if the serialised data contains information about a field |
| 239 | * which does actually not exist in the class we know of |
| 240 | * @throws NoSuchMethodException |
| 241 | * if a class described in the serialised data cannot be created |
| 242 | * because it is not compatible with this code |
| 243 | * @throws ClassNotFoundException |
| 244 | * if a class described in the serialised data cannot be found |
| 245 | * @throws java.lang.NullPointerException |
| 246 | * if the counter part has no data to send |
| 247 | */ |
| 248 | protected Object recObject() throws IOException, NoSuchFieldException, |
| 249 | NoSuchMethodException, ClassNotFoundException, |
| 250 | java.lang.NullPointerException { |
| 251 | String str = recString(); |
| 252 | if (str == null) { |
| 253 | throw new NullPointerException("No more data available"); |
| 254 | } |
| 255 | |
| 256 | return new Importer().read(str).getValue(); |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * Send the given string to the counter part (and, only for client, return |
| 261 | * the answer -- the server will always receive NULL). |
| 262 | * |
| 263 | * @param line |
| 264 | * the data to send (we will add a line feed) |
| 265 | * |
| 266 | * @return the answer if this action is a client (without the added line |
| 267 | * feed), NULL if it is a server |
| 268 | * |
| 269 | * @throws IOException |
| 270 | * in case of I/O error |
| 271 | */ |
| 272 | protected String sendString(String line) throws IOException { |
| 273 | synchronized (lock) { |
| 274 | out.write(line); |
| 275 | out.write("\n"); |
| 276 | bytesSent += line.length() + 1; |
| 277 | |
| 278 | if (server) { |
| 279 | out.flush(); |
| 280 | return null; |
| 281 | } |
| 282 | |
| 283 | contentToSend = true; |
| 284 | return recString(); |
| 285 | } |
| 286 | } |
| 287 | |
| 288 | /** |
| 289 | * Reserved for the server (externally): flush the data to the client and |
| 290 | * retrieve its answer. |
| 291 | * <p> |
| 292 | * Also used internally for the client (only do something if there is |
| 293 | * contentToSend). |
| 294 | * <p> |
| 295 | * Will only flush the data if there is contentToSend. |
| 296 | * |
| 297 | * @return the answer (which can be NULL) |
| 298 | * |
| 299 | * @throws IOException |
| 300 | * in case of I/O error |
| 301 | */ |
| 302 | protected String recString() throws IOException { |
| 303 | synchronized (lock) { |
| 304 | if (server || contentToSend) { |
| 305 | if (contentToSend) { |
| 306 | out.flush(); |
| 307 | contentToSend = false; |
| 308 | } |
| 309 | |
| 310 | String line = in.readLine(); |
| 311 | if (line != null) { |
| 312 | bytesReceived += line.length(); |
| 313 | } |
| 314 | |
| 315 | return line; |
| 316 | } |
| 317 | |
| 318 | return null; |
| 319 | } |
| 320 | } |
| 321 | } |