src/be/nikiroo/utils/serial/SerialUtils.java

   1 package be.nikiroo.utils.serial;
   2
   3 import java.io.ByteArrayInputStream;
   4 import java.io.IOException;
   5 import java.io.InputStream;
   6 import java.io.NotSerializableException;
   7 import java.io.OutputStream;
   8 import java.io.UnsupportedEncodingException;
   9 import java.lang.reflect.Array;
  10 import java.lang.reflect.Constructor;
  11 import java.lang.reflect.Field;
  12 import java.lang.reflect.Modifier;
  13 import java.net.URL;
  14 import java.util.ArrayList;
  15 import java.util.HashMap;
  16 import java.util.List;
  17 import java.util.Map;
  18 import java.util.UnknownFormatConversionException;
  19
  20 import be.nikiroo.utils.IOUtils;
  21 import be.nikiroo.utils.Image;
  22 import be.nikiroo.utils.NextableInputStream;
  23 import be.nikiroo.utils.NextableInputStreamStep;
  24 import be.nikiroo.utils.StringUtils;
  25
  26 /**
  27  * Small class to help with serialisation.
  28  * <p>
  29  * Note that we do not support inner classes (but we do support nested classes)
  30  * and all objects require an empty constructor to be deserialised.
  31  * <p>
  32  * It is possible to add support to custom types (both the encoder and the
  33  * decoder will require the custom classes) -- see {@link CustomSerializer}.
  34  * <p>
  35  * Default supported types are:
  36  * <ul>
  37  * <li>NULL (as a null value)</li>
  38  * <li>String</li>
  39  * <li>Boolean</li>
  40  * <li>Byte</li>
  41  * <li>Character</li>
  42  * <li>Short</li>
  43  * <li>Long</li>
  44  * <li>Float</li>
  45  * <li>Double</li>
  46  * <li>Integer</li>
  47  * <li>Enum (any enum whose name and value is known by the caller)</li>
  48  * <li>java.awt.image.BufferedImage (as a {@link CustomSerializer})</li>
  49  * <li>An array of the above (as a {@link CustomSerializer})</li>
  50  * <li>URL</li>
  51  * </ul>
  52  *
  53  * @author niki
  54  */
  55 public class SerialUtils {
  56         private static Map<String, CustomSerializer> customTypes;
  57
  58         static {
  59                 customTypes = new HashMap<String, CustomSerializer>();
  60
  61                 // Array types:
  62                 customTypes.put("[]", new CustomSerializer() {
  63                         @Override
  64                         protected void toStream(OutputStream out, Object value)
  65                                         throws IOException {
  66                                 // TODO: we use \n to separate, and b64 to un-\n -- but we could
  67                                 // use \\n ?
  68                                 String type = value.getClass().getCanonicalName();
  69                                 type = type.substring(0, type.length() - 2); // remove the []
  70
  71                                 write(out, type);
  72                                 write(out, "\n");
  73                                 try {
  74                                         for (int i = 0; true; i++) {
  75                                                 Object item = Array.get(value, i);
  76                                                 // encode it normally if direct value
  77                                                 if (!SerialUtils.encode(out, item)) {
  78                                                         try {
  79                                                                 // TODO: use ZIP: if not?
  80                                                                 new Exporter(out).append(item);
  81                                                         } catch (NotSerializableException e) {
  82                                                                 throw new UnknownFormatConversionException(e
  83                                                                                 .getMessage());
  84                                                         }
  85                                                 }
  86                                                 write(out, "\n");
  87                                         }
  88                                 } catch (ArrayIndexOutOfBoundsException e) {
  89                                         // Done.
  90                                 }
  91                         }
  92
  93                         @Override
  94                         protected Object fromStream(InputStream in) throws IOException {
  95                                 NextableInputStream stream = new NextableInputStream(in,
  96                                                 new NextableInputStreamStep('\n'));
  97
  98                                 try {
  99                                         List<Object> list = new ArrayList<Object>();
 100                                         stream.next();
 101                                         String type = IOUtils.readSmallStream(stream);
 102
 103                                         while (stream.next()) {
 104                                                 Object value = new Importer().read(stream).getValue();
 105                                                 list.add(value);
 106                                         }
 107
 108                                         Object array = Array.newInstance(
 109                                                         SerialUtils.getClass(type), list.size());
 110                                         for (int i = 0; i < list.size(); i++) {
 111                                                 Array.set(array, i, list.get(i));
 112                                         }
 113
 114                                         return array;
 115                                 } catch (Exception e) {
 116                                         if (e instanceof IOException) {
 117                                                 throw (IOException) e;
 118                                         }
 119                                         throw new IOException(e.getMessage());
 120                                 }
 121                         }
 122
 123                         @Override
 124                         protected String getType() {
 125                                 return "[]";
 126                         }
 127                 });
 128
 129                 // URL:
 130                 customTypes.put("java.net.URL", new CustomSerializer() {
 131
 132                         @Override
 133                         protected void toStream(OutputStream out, Object value)
 134                                         throws IOException {
 135                                 String val = "";
 136                                 if (value != null) {
 137                                         val = ((URL) value).toString();
 138                                 }
 139
 140                                 out.write(val.getBytes("UTF-8"));
 141                         }
 142
 143                         @Override
 144                         protected Object fromStream(InputStream in) throws IOException {
 145                                 String val = IOUtils.readSmallStream(in);
 146                                 if (!val.isEmpty()) {
 147                                         return new URL(val);
 148                                 }
 149
 150                                 return null;
 151                         }
 152
 153                         @Override
 154                         protected String getType() {
 155                                 return "java.net.URL";
 156                         }
 157                 });
 158
 159                 // Images (this is currently the only supported image type by default)
 160                 customTypes.put("be.nikiroo.utils.Image", new CustomSerializer() {
 161                         @Override
 162                         protected void toStream(OutputStream out, Object value)
 163                                         throws IOException {
 164                                 Image img = (Image) value;
 165                                 OutputStream encoded = StringUtils.base64(out, false, false);
 166                                 try {
 167                                         InputStream in = img.newInputStream();
 168                                         try {
 169                                                 IOUtils.write(in, encoded);
 170                                         } finally {
 171                                                 in.close();
 172                                         }
 173                                 } finally {
 174                                         encoded.close();
 175                                 }
 176                         }
 177
 178                         @Override
 179                         protected String getType() {
 180                                 return "be.nikiroo.utils.Image";
 181                         }
 182
 183                         @Override
 184                         protected Object fromStream(InputStream in) throws IOException {
 185                                 try {
 186                                         return new Image(in);
 187                                 } catch (IOException e) {
 188                                         throw new UnknownFormatConversionException(e.getMessage());
 189                                 }
 190                         }
 191                 });
 192         }
 193
 194         /**
 195          * Create an empty object of the given type.
 196          *
 197          * @param type
 198          *            the object type (its class name)
 199          *
 200          * @return the new object
 201          *
 202          * @throws ClassNotFoundException
 203          *             if the class cannot be found
 204          * @throws NoSuchMethodException
 205          *             if the given class is not compatible with this code
 206          */
 207         public static Object createObject(String type)
 208                         throws ClassNotFoundException, NoSuchMethodException {
 209
 210                 String desc = null;
 211                 try {
 212                         Class<?> clazz = getClass(type);
 213                         String className = clazz.getName();
 214                         List<Object> args = new ArrayList<Object>();
 215                         List<Class<?>> classes = new ArrayList<Class<?>>();
 216                         Constructor<?> ctor = null;
 217                         if (className.contains("$")) {
 218                                 for (String parentName = className.substring(0,
 219                                                 className.lastIndexOf('$'));; parentName = parentName
 220                                                 .substring(0, parentName.lastIndexOf('$'))) {
 221                                         Object parent = createObject(parentName);
 222                                         args.add(parent);
 223                                         classes.add(parent.getClass());
 224
 225                                         if (!parentName.contains("$")) {
 226                                                 break;
 227                                         }
 228                                 }
 229
 230                                 // Better error description in case there is no empty
 231                                 // constructor:
 232                                 desc = "";
 233                                 String end = "";
 234                                 for (Class<?> parent = clazz; parent != null
 235                                                 && !parent.equals(Object.class); parent = parent
 236                                                 .getSuperclass()) {
 237                                         if (!desc.isEmpty()) {
 238                                                 desc += " [:";
 239                                                 end += "]";
 240                                         }
 241                                         desc += parent;
 242                                 }
 243                                 desc += end;
 244                                 //
 245
 246                                 try {
 247                                         ctor = clazz.getDeclaredConstructor(classes
 248                                                         .toArray(new Class[] {}));
 249                                 } catch (NoSuchMethodException nsme) {
 250                                         // TODO: it seems we do not always need a parameter for each
 251                                         // level, so we currently try "ALL" levels or "FIRST" level
 252                                         // only -> we should check the actual rule and use it
 253                                         ctor = clazz.getDeclaredConstructor(classes.get(0));
 254                                         Object firstParent = args.get(0);
 255                                         args.clear();
 256                                         args.add(firstParent);
 257                                 }
 258                                 desc = null;
 259                         } else {
 260                                 ctor = clazz.getDeclaredConstructor();
 261                         }
 262
 263                         ctor.setAccessible(true);
 264                         return ctor.newInstance(args.toArray());
 265                 } catch (ClassNotFoundException e) {
 266                         throw e;
 267                 } catch (NoSuchMethodException e) {
 268                         if (desc != null) {
 269                                 throw new NoSuchMethodException("Empty constructor not found: "
 270                                                 + desc);
 271                         }
 272                         throw e;
 273                 } catch (Exception e) {
 274                         throw new NoSuchMethodException("Cannot instantiate: " + type);
 275                 }
 276         }
 277
 278         /**
 279          * Insert a custom serialiser that will take precedence over the default one
 280          * or the target class.
 281          *
 282          * @param serializer
 283          *            the custom serialiser
 284          */
 285         static public void addCustomSerializer(CustomSerializer serializer) {
 286                 customTypes.put(serializer.getType(), serializer);
 287         }
 288
 289         /**
 290          * Serialise the given object into this {@link OutputStream}.
 291          * <p>
 292          * <b>Important: </b>If the operation fails (with a
 293          * {@link NotSerializableException}), the {@link StringBuilder} will be
 294          * corrupted (will contain bad, most probably not importable data).
 295          *
 296          * @param out
 297          *            the output {@link OutputStream} to serialise to
 298          * @param o
 299          *            the object to serialise
 300          * @param map
 301          *            the map of already serialised objects (if the given object or
 302          *            one of its descendant is already present in it, only an ID
 303          *            will be serialised)
 304          *
 305          * @throws NotSerializableException
 306          *             if the object cannot be serialised (in this case, the
 307          *             {@link StringBuilder} can contain bad, most probably not
 308          *             importable data)
 309          * @throws IOException
 310          *             in case of I/O errors
 311          */
 312         static void append(OutputStream out, Object o, Map<Integer, Object> map)
 313                         throws NotSerializableException, IOException {
 314
 315                 Field[] fields = new Field[] {};
 316                 String type = "";
 317                 String id = "NULL";
 318
 319                 if (o != null) {
 320                         int hash = System.identityHashCode(o);
 321                         fields = o.getClass().getDeclaredFields();
 322                         type = o.getClass().getCanonicalName();
 323                         if (type == null) {
 324                                 // Anonymous inner classes support
 325                                 type = o.getClass().getName();
 326                         }
 327                         id = Integer.toString(hash);
 328                         if (map.containsKey(hash)) {
 329                                 fields = new Field[] {};
 330                         } else {
 331                                 map.put(hash, o);
 332                         }
 333                 }
 334
 335                 write(out, "{\nREF ");
 336                 write(out, type);
 337                 write(out, "@");
 338                 write(out, id);
 339                 write(out, ":");
 340
 341                 if (!encode(out, o)) { // check if direct value
 342                         try {
 343                                 for (Field field : fields) {
 344                                         field.setAccessible(true);
 345
 346                                         if (field.getName().startsWith("this$")
 347                                                         || field.isSynthetic()
 348                                                         || (field.getModifiers() & Modifier.STATIC) == Modifier.STATIC) {
 349                                                 // Do not keep this links of nested classes
 350                                                 // Do not keep synthetic fields
 351                                                 // Do not keep final fields
 352                                                 continue;
 353                                         }
 354
 355                                         write(out, "\n");
 356                                         write(out, field.getName());
 357                                         write(out, ":");
 358
 359                                         Object value = field.get(o);
 360
 361                                         if (!encode(out, value)) {
 362                                                 write(out, "\n");
 363                                                 append(out, value, map);
 364                                         }
 365                                 }
 366                         } catch (IllegalArgumentException e) {
 367                                 e.printStackTrace(); // should not happen (see
 368                                                                                 // setAccessible)
 369                         } catch (IllegalAccessException e) {
 370                                 e.printStackTrace(); // should not happen (see
 371                                                                                 // setAccessible)
 372                         }
 373                 }
 374                 write(out, "\n}");
 375         }
 376
 377         /**
 378          * Encode the object into the given {@link OutputStream} if possible and if
 379          * supported.
 380          * <p>
 381          * A supported object in this context means an object we can directly
 382          * encode, like an Integer or a String. Custom objects and arrays are also
 383          * considered supported, but <b>compound objects are not supported here</b>.
 384          * <p>
 385          * For compound objects, you should use {@link Exporter}.
 386          *
 387          * @param out
 388          *            the {@link OutputStream} to append to
 389          * @param value
 390          *            the object to encode (can be NULL, which will be encoded)
 391          *
 392          * @return TRUE if success, FALSE if not (the content of the
 393          *         {@link OutputStream} won't be changed in case of failure)
 394          *
 395          * @throws IOException
 396          *             in case of I/O error
 397          */
 398         static boolean encode(OutputStream out, Object value) throws IOException {
 399                 if (value == null) {
 400                         write(out, "NULL");
 401                 } else if (value.getClass().getSimpleName().endsWith("[]")) {
 402                         // Simple name does support [] suffix and do not return NULL for
 403                         // inner anonymous classes
 404                         return customTypes.get("[]").encode(out, value);
 405                 } else if (customTypes.containsKey(value.getClass().getCanonicalName())) {
 406                         return customTypes.get(value.getClass().getCanonicalName())//
 407                                         .encode(out, value);
 408                 } else if (value instanceof String) {
 409                         encodeString(out, (String) value);
 410                 } else if (value instanceof Boolean) {
 411                         write(out, value);
 412                 } else if (value instanceof Byte) {
 413                         write(out, value);
 414                         write(out, "b");
 415                 } else if (value instanceof Character) {
 416                         encodeString(out, "" + value);
 417                         write(out, "c");
 418                 } else if (value instanceof Short) {
 419                         write(out, value);
 420                         write(out, "s");
 421                 } else if (value instanceof Integer) {
 422                         write(out, value);
 423                 } else if (value instanceof Long) {
 424                         write(out, value);
 425                         write(out, "L");
 426                 } else if (value instanceof Float) {
 427                         write(out, value);
 428                         write(out, "F");
 429                 } else if (value instanceof Double) {
 430                         write(out, value);
 431                         write(out, "d");
 432                 } else if (value instanceof Enum) {
 433                         String type = value.getClass().getCanonicalName();
 434                         write(out, type);
 435                         write(out, ".");
 436                         write(out, ((Enum<?>) value).name());
 437                         write(out, ";");
 438                 } else {
 439                         return false;
 440                 }
 441
 442                 return true;
 443         }
 444
 445         /**
 446          * Decode the data into an equivalent supported source object.
 447          * <p>
 448          * A supported object in this context means an object we can directly
 449          * encode, like an Integer or a String. Custom objects and arrays are also
 450          * considered supported, but <b>compound objects are not supported here</b>.
 451          * <p>
 452          * For compound objects, you should use {@link Importer}.
 453          *
 454          * @param encodedValue
 455          *            the encoded data, cannot be NULL
 456          *
 457          * @return the object (can be NULL for NULL encoded values)
 458          *
 459          * @throws IOException
 460          *             if the content cannot be converted
 461          */
 462         static Object decode(String encodedValue) throws IOException {
 463                 try {
 464                         String cut = "";
 465                         if (encodedValue.length() > 1) {
 466                                 cut = encodedValue.substring(0, encodedValue.length() - 1);
 467                         }
 468
 469                         if (CustomSerializer.isCustom(encodedValue)) {
 470                                 // custom:TYPE_NAME:"content is String-encoded"
 471                                 String type = CustomSerializer.typeOf(encodedValue);
 472                                 if (customTypes.containsKey(type)) {
 473                                         // TODO: we should start with a stream
 474                                         InputStream streamEncodedValue = new ByteArrayInputStream(
 475                                                         encodedValue.getBytes("UTF-8"));
 476                                         try {
 477                                                 return customTypes.get(type).decode(streamEncodedValue);
 478                                         } finally {
 479                                                 streamEncodedValue.close();
 480                                         }
 481                                 }
 482                                 throw new IOException("Unknown custom type: " + type);
 483                         } else if (encodedValue.equals("NULL")
 484                                         || encodedValue.equals("null")) {
 485                                 return null;
 486                         } else if (encodedValue.endsWith("\"")) {
 487                                 return decodeString(encodedValue);
 488                         } else if (encodedValue.equals("true")) {
 489                                 return true;
 490                         } else if (encodedValue.equals("false")) {
 491                                 return false;
 492                         } else if (encodedValue.endsWith("b")) {
 493                                 return Byte.parseByte(cut);
 494                         } else if (encodedValue.endsWith("c")) {
 495                                 return decodeString(cut).charAt(0);
 496                         } else if (encodedValue.endsWith("s")) {
 497                                 return Short.parseShort(cut);
 498                         } else if (encodedValue.endsWith("L")) {
 499                                 return Long.parseLong(cut);
 500                         } else if (encodedValue.endsWith("F")) {
 501                                 return Float.parseFloat(cut);
 502                         } else if (encodedValue.endsWith("d")) {
 503                                 return Double.parseDouble(cut);
 504                         } else if (encodedValue.endsWith(";")) {
 505                                 return decodeEnum(encodedValue);
 506                         } else {
 507                                 return Integer.parseInt(encodedValue);
 508                         }
 509                 } catch (Exception e) {
 510                         if (e instanceof IOException) {
 511                                 throw (IOException) e;
 512                         }
 513                         throw new IOException(e.getMessage());
 514                 }
 515         }
 516
 517         /**
 518          * Write the given {@link String} into the given {@link OutputStream} in
 519          * UTF-8.
 520          *
 521          * @param out
 522          *            the {@link OutputStream}
 523          * @param data
 524          *            the data to write, cannot be NULL
 525          *
 526          * @throws IOException
 527          *             in case of I/O error
 528          */
 529         static void write(OutputStream out, Object data) throws IOException {
 530                 try {
 531                         out.write(data.toString().getBytes("UTF-8"));
 532                 } catch (UnsupportedEncodingException e) {
 533                         // A conforming JVM is required to support UTF-8
 534                         e.printStackTrace();
 535                 }
 536         }
 537
 538         /**
 539          * Return the corresponding class or throw an {@link Exception} if it
 540          * cannot.
 541          *
 542          * @param type
 543          *            the class name to look for
 544          *
 545          * @return the class (will never be NULL)
 546          *
 547          * @throws ClassNotFoundException
 548          *             if the class cannot be found
 549          * @throws NoSuchMethodException
 550          *             if the class cannot be created (usually because it or its
 551          *             enclosing class doesn't have an empty constructor)
 552          */
 553         static private Class<?> getClass(String type)
 554                         throws ClassNotFoundException, NoSuchMethodException {
 555                 Class<?> clazz = null;
 556                 try {
 557                         clazz = Class.forName(type);
 558                 } catch (ClassNotFoundException e) {
 559                         int pos = type.length();
 560                         pos = type.lastIndexOf(".", pos);
 561                         if (pos >= 0) {
 562                                 String parentType = type.substring(0, pos);
 563                                 String nestedType = type.substring(pos + 1);
 564                                 Class<?> javaParent = null;
 565                                 try {
 566                                         javaParent = getClass(parentType);
 567                                         parentType = javaParent.getName();
 568                                         clazz = Class.forName(parentType + "$" + nestedType);
 569                                 } catch (Exception ee) {
 570                                 }
 571
 572                                 if (javaParent == null) {
 573                                         throw new NoSuchMethodException(
 574                                                         "Class not found: "
 575                                                                         + type
 576                                                                         + " (the enclosing class cannot be created: maybe it doesn't have an empty constructor?)");
 577                                 }
 578                         }
 579                 }
 580
 581                 if (clazz == null) {
 582                         throw new ClassNotFoundException("Class not found: " + type);
 583                 }
 584
 585                 return clazz;
 586         }
 587
 588         @SuppressWarnings({ "unchecked", "rawtypes" })
 589         static private Enum<?> decodeEnum(String escaped) {
 590                 // escaped: be.xxx.EnumType.VALUE;
 591                 int pos = escaped.lastIndexOf(".");
 592                 String type = escaped.substring(0, pos);
 593                 String name = escaped.substring(pos + 1, escaped.length() - 1);
 594
 595                 try {
 596                         return Enum.valueOf((Class<Enum>) getClass(type), name);
 597                 } catch (Exception e) {
 598                         throw new UnknownFormatConversionException("Unknown enum: <" + type
 599                                         + "> " + name);
 600                 }
 601         }
 602
 603         // aa bb -> "aa\tbb"
 604         static void encodeString(OutputStream out, String raw) throws IOException {
 605                 out.write('\"');
 606                 // TODO !! utf-8 required
 607                 for (char car : raw.toCharArray()) {
 608                         encodeString(out, car);
 609                 }
 610                 out.write('\"');
 611         }
 612
 613         // aa bb -> "aa\tbb"
 614         static void encodeString(OutputStream out, InputStream raw)
 615                         throws IOException {
 616                 out.write('\"');
 617                 byte buffer[] = new byte[4096];
 618                 for (int len = 0; (len = raw.read(buffer)) > 0;) {
 619                         for (int i = 0; i < len; i++) {
 620                                 // TODO: not 100% correct, look up howto for UTF-8
 621                                 encodeString(out, (char) buffer[i]);
 622                         }
 623                 }
 624                 out.write('\"');
 625         }
 626
 627         // for encode string, NOT to encode a char by itself!
 628         static void encodeString(OutputStream out, char raw) throws IOException {
 629                 switch (raw) {
 630                 case '\\':
 631                         out.write('\\');
 632                         out.write('\\');
 633                         break;
 634                 case '\r':
 635                         out.write('\\');
 636                         out.write('r');
 637                         break;
 638                 case '\n':
 639                         out.write('\\');
 640                         out.write('n');
 641                         break;
 642                 case '"':
 643                         out.write('\\');
 644                         out.write('\"');
 645                         break;
 646                 default:
 647                         out.write(raw);
 648                         break;
 649                 }
 650         }
 651
 652         // "aa\tbb" -> aa bb
 653         static String decodeString(String escaped) {
 654                 StringBuilder builder = new StringBuilder();
 655
 656                 boolean escaping = false;
 657                 for (char car : escaped.toCharArray()) {
 658                         if (!escaping) {
 659                                 if (car == '\\') {
 660                                         escaping = true;
 661                                 } else {
 662                                         builder.append(car);
 663                                 }
 664                         } else {
 665                                 switch (car) {
 666                                 case '\\':
 667                                         builder.append('\\');
 668                                         break;
 669                                 case 'r':
 670                                         builder.append('\r');
 671                                         break;
 672                                 case 'n':
 673                                         builder.append('\n');
 674                                         break;
 675                                 case '"':
 676                                         builder.append('"');
 677                                         break;
 678                                 }
 679                                 escaping = false;
 680                         }
 681                 }
 682
 683                 return builder.substring(1, builder.length() - 1);
 684         }
 685 }