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.streams.NextableInputStream;
  23 import be.nikiroo.utils.streams.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, "\r");
  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: bad escaping?
  80                                                                 write(out, "B64:");
  81                                                                 OutputStream bout = StringUtils.base64(out,
  82                                                                                 false, false);
  83                                                                 new Exporter(bout).append(item);
  84                                                         } catch (NotSerializableException e) {
  85                                                                 throw new UnknownFormatConversionException(e
  86                                                                                 .getMessage());
  87                                                         }
  88                                                 }
  89                                                 write(out, "\r");
  90                                         }
  91                                 } catch (ArrayIndexOutOfBoundsException e) {
  92                                         // Done.
  93                                 }
  94                         }
  95
  96                         @Override
  97                         protected Object fromStream(InputStream in) throws IOException {
  98                                 NextableInputStream stream = new NextableInputStream(in,
  99                                                 new NextableInputStreamStep('\r'));
 100
 101                                 try {
 102                                         List<Object> list = new ArrayList<Object>();
 103                                         stream.next();
 104                                         String type = IOUtils.readSmallStream(stream);
 105
 106                                         while (stream.next()) {
 107                                                 Object value = new Importer().read(stream).getValue();
 108                                                 list.add(value);
 109                                         }
 110
 111                                         Object array = Array.newInstance(
 112                                                         SerialUtils.getClass(type), list.size());
 113                                         for (int i = 0; i < list.size(); i++) {
 114                                                 Array.set(array, i, list.get(i));
 115                                         }
 116
 117                                         return array;
 118                                 } catch (Exception e) {
 119                                         if (e instanceof IOException) {
 120                                                 throw (IOException) e;
 121                                         }
 122                                         throw new IOException(e.getMessage());
 123                                 }
 124                         }
 125
 126                         @Override
 127                         protected String getType() {
 128                                 return "[]";
 129                         }
 130                 });
 131
 132                 // URL:
 133                 customTypes.put("java.net.URL", new CustomSerializer() {
 134                         @Override
 135                         protected void toStream(OutputStream out, Object value)
 136                                         throws IOException {
 137                                 String val = "";
 138                                 if (value != null) {
 139                                         val = ((URL) value).toString();
 140                                 }
 141
 142                                 out.write(val.getBytes("UTF-8"));
 143                         }
 144
 145                         @Override
 146                         protected Object fromStream(InputStream in) throws IOException {
 147                                 String val = IOUtils.readSmallStream(in);
 148                                 if (!val.isEmpty()) {
 149                                         return new URL(val);
 150                                 }
 151
 152                                 return null;
 153                         }
 154
 155                         @Override
 156                         protected String getType() {
 157                                 return "java.net.URL";
 158                         }
 159                 });
 160
 161                 // Images (this is currently the only supported image type by default)
 162                 customTypes.put("be.nikiroo.utils.Image", new CustomSerializer() {
 163                         @Override
 164                         protected void toStream(OutputStream out, Object value)
 165                                         throws IOException {
 166                                 Image img = (Image) value;
 167                                 OutputStream encoded = StringUtils.base64(out, false, false);
 168                                 try {
 169                                         InputStream in = img.newInputStream();
 170                                         try {
 171                                                 IOUtils.write(in, encoded);
 172                                         } finally {
 173                                                 in.close();
 174                                         }
 175                                 } finally {
 176                                         encoded.close();
 177                                 }
 178                         }
 179
 180                         @Override
 181                         protected String getType() {
 182                                 return "be.nikiroo.utils.Image";
 183                         }
 184
 185                         @Override
 186                         protected Object fromStream(InputStream in) throws IOException {
 187                                 try {
 188                                         return new Image(in);
 189                                 } catch (IOException e) {
 190                                         throw new UnknownFormatConversionException(e.getMessage());
 191                                 }
 192                         }
 193                 });
 194         }
 195
 196         /**
 197          * Create an empty object of the given type.
 198          *
 199          * @param type
 200          *            the object type (its class name)
 201          *
 202          * @return the new object
 203          *
 204          * @throws ClassNotFoundException
 205          *             if the class cannot be found
 206          * @throws NoSuchMethodException
 207          *             if the given class is not compatible with this code
 208          */
 209         public static Object createObject(String type)
 210                         throws ClassNotFoundException, NoSuchMethodException {
 211
 212                 String desc = null;
 213                 try {
 214                         Class<?> clazz = getClass(type);
 215                         String className = clazz.getName();
 216                         List<Object> args = new ArrayList<Object>();
 217                         List<Class<?>> classes = new ArrayList<Class<?>>();
 218                         Constructor<?> ctor = null;
 219                         if (className.contains("$")) {
 220                                 for (String parentName = className.substring(0,
 221                                                 className.lastIndexOf('$'));; parentName = parentName
 222                                                 .substring(0, parentName.lastIndexOf('$'))) {
 223                                         Object parent = createObject(parentName);
 224                                         args.add(parent);
 225                                         classes.add(parent.getClass());
 226
 227                                         if (!parentName.contains("$")) {
 228                                                 break;
 229                                         }
 230                                 }
 231
 232                                 // Better error description in case there is no empty
 233                                 // constructor:
 234                                 desc = "";
 235                                 String end = "";
 236                                 for (Class<?> parent = clazz; parent != null
 237                                                 && !parent.equals(Object.class); parent = parent
 238                                                 .getSuperclass()) {
 239                                         if (!desc.isEmpty()) {
 240                                                 desc += " [:";
 241                                                 end += "]";
 242                                         }
 243                                         desc += parent;
 244                                 }
 245                                 desc += end;
 246                                 //
 247
 248                                 try {
 249                                         ctor = clazz.getDeclaredConstructor(classes
 250                                                         .toArray(new Class[] {}));
 251                                 } catch (NoSuchMethodException nsme) {
 252                                         // TODO: it seems we do not always need a parameter for each
 253                                         // level, so we currently try "ALL" levels or "FIRST" level
 254                                         // only -> we should check the actual rule and use it
 255                                         ctor = clazz.getDeclaredConstructor(classes.get(0));
 256                                         Object firstParent = args.get(0);
 257                                         args.clear();
 258                                         args.add(firstParent);
 259                                 }
 260                                 desc = null;
 261                         } else {
 262                                 ctor = clazz.getDeclaredConstructor();
 263                         }
 264
 265                         ctor.setAccessible(true);
 266                         return ctor.newInstance(args.toArray());
 267                 } catch (ClassNotFoundException e) {
 268                         throw e;
 269                 } catch (NoSuchMethodException e) {
 270                         if (desc != null) {
 271                                 throw new NoSuchMethodException("Empty constructor not found: "
 272                                                 + desc);
 273                         }
 274                         throw e;
 275                 } catch (Exception e) {
 276                         throw new NoSuchMethodException("Cannot instantiate: " + type);
 277                 }
 278         }
 279
 280         /**
 281          * Insert a custom serialiser that will take precedence over the default one
 282          * or the target class.
 283          *
 284          * @param serializer
 285          *            the custom serialiser
 286          */
 287         static public void addCustomSerializer(CustomSerializer serializer) {
 288                 customTypes.put(serializer.getType(), serializer);
 289         }
 290
 291         /**
 292          * Serialise the given object into this {@link OutputStream}.
 293          * <p>
 294          * <b>Important: </b>If the operation fails (with a
 295          * {@link NotSerializableException}), the {@link StringBuilder} will be
 296          * corrupted (will contain bad, most probably not importable data).
 297          *
 298          * @param out
 299          *            the output {@link OutputStream} to serialise to
 300          * @param o
 301          *            the object to serialise
 302          * @param map
 303          *            the map of already serialised objects (if the given object or
 304          *            one of its descendant is already present in it, only an ID
 305          *            will be serialised)
 306          *
 307          * @throws NotSerializableException
 308          *             if the object cannot be serialised (in this case, the
 309          *             {@link StringBuilder} can contain bad, most probably not
 310          *             importable data)
 311          * @throws IOException
 312          *             in case of I/O errors
 313          */
 314         static void append(OutputStream out, Object o, Map<Integer, Object> map)
 315                         throws NotSerializableException, IOException {
 316
 317                 Field[] fields = new Field[] {};
 318                 String type = "";
 319                 String id = "NULL";
 320
 321                 if (o != null) {
 322                         int hash = System.identityHashCode(o);
 323                         fields = o.getClass().getDeclaredFields();
 324                         type = o.getClass().getCanonicalName();
 325                         if (type == null) {
 326                                 // Anonymous inner classes support
 327                                 type = o.getClass().getName();
 328                         }
 329                         id = Integer.toString(hash);
 330                         if (map.containsKey(hash)) {
 331                                 fields = new Field[] {};
 332                         } else {
 333                                 map.put(hash, o);
 334                         }
 335                 }
 336
 337                 write(out, "{\nREF ");
 338                 write(out, type);
 339                 write(out, "@");
 340                 write(out, id);
 341                 write(out, ":");
 342
 343                 if (!encode(out, o)) { // check if direct value
 344                         try {
 345                                 for (Field field : fields) {
 346                                         field.setAccessible(true);
 347
 348                                         if (field.getName().startsWith("this$")
 349                                                         || field.isSynthetic()
 350                                                         || (field.getModifiers() & Modifier.STATIC) == Modifier.STATIC) {
 351                                                 // Do not keep this links of nested classes
 352                                                 // Do not keep synthetic fields
 353                                                 // Do not keep final fields
 354                                                 continue;
 355                                         }
 356
 357                                         write(out, "\n");
 358                                         write(out, field.getName());
 359                                         write(out, ":");
 360
 361                                         Object value = field.get(o);
 362
 363                                         if (!encode(out, value)) {
 364                                                 write(out, "\n");
 365                                                 append(out, value, map);
 366                                         }
 367                                 }
 368                         } catch (IllegalArgumentException e) {
 369                                 e.printStackTrace(); // should not happen (see
 370                                                                                 // setAccessible)
 371                         } catch (IllegalAccessException e) {
 372                                 e.printStackTrace(); // should not happen (see
 373                                                                                 // setAccessible)
 374                         }
 375                 }
 376                 write(out, "\n}");
 377         }
 378
 379         /**
 380          * Encode the object into the given {@link OutputStream} if possible and if
 381          * supported.
 382          * <p>
 383          * A supported object in this context means an object we can directly
 384          * encode, like an Integer or a String. Custom objects and arrays are also
 385          * considered supported, but <b>compound objects are not supported here</b>.
 386          * <p>
 387          * For compound objects, you should use {@link Exporter}.
 388          *
 389          * @param out
 390          *            the {@link OutputStream} to append to
 391          * @param value
 392          *            the object to encode (can be NULL, which will be encoded)
 393          *
 394          * @return TRUE if success, FALSE if not (the content of the
 395          *         {@link OutputStream} won't be changed in case of failure)
 396          *
 397          * @throws IOException
 398          *             in case of I/O error
 399          */
 400         static boolean encode(OutputStream out, Object value) throws IOException {
 401                 if (value == null) {
 402                         write(out, "NULL");
 403                 } else if (value.getClass().getSimpleName().endsWith("[]")) {
 404                         // Simple name does support [] suffix and do not return NULL for
 405                         // inner anonymous classes
 406                         return customTypes.get("[]").encode(out, value);
 407                 } else if (customTypes.containsKey(value.getClass().getCanonicalName())) {
 408                         return customTypes.get(value.getClass().getCanonicalName())//
 409                                         .encode(out, value);
 410                 } else if (value instanceof String) {
 411                         encodeString(out, (String) value);
 412                 } else if (value instanceof Boolean) {
 413                         write(out, value);
 414                 } else if (value instanceof Byte) {
 415                         write(out, value);
 416                         write(out, "b");
 417                 } else if (value instanceof Character) {
 418                         encodeString(out, "" + value);
 419                         write(out, "c");
 420                 } else if (value instanceof Short) {
 421                         write(out, value);
 422                         write(out, "s");
 423                 } else if (value instanceof Integer) {
 424                         write(out, value);
 425                 } else if (value instanceof Long) {
 426                         write(out, value);
 427                         write(out, "L");
 428                 } else if (value instanceof Float) {
 429                         write(out, value);
 430                         write(out, "F");
 431                 } else if (value instanceof Double) {
 432                         write(out, value);
 433                         write(out, "d");
 434                 } else if (value instanceof Enum) {
 435                         String type = value.getClass().getCanonicalName();
 436                         write(out, type);
 437                         write(out, ".");
 438                         write(out, ((Enum<?>) value).name());
 439                         write(out, ";");
 440                 } else {
 441                         return false;
 442                 }
 443
 444                 return true;
 445         }
 446
 447         /**
 448          * Decode the data into an equivalent supported source object.
 449          * <p>
 450          * A supported object in this context means an object we can directly
 451          * encode, like an Integer or a String. Custom objects and arrays are also
 452          * considered supported, but <b>compound objects are not supported here</b>.
 453          * <p>
 454          * For compound objects, you should use {@link Importer}.
 455          *
 456          * @param encodedValue
 457          *            the encoded data, cannot be NULL
 458          *
 459          * @return the object (can be NULL for NULL encoded values)
 460          *
 461          * @throws IOException
 462          *             if the content cannot be converted
 463          */
 464         static Object decode(String encodedValue) throws IOException {
 465                 try {
 466                         String cut = "";
 467                         if (encodedValue.length() > 1) {
 468                                 cut = encodedValue.substring(0, encodedValue.length() - 1);
 469                         }
 470
 471                         if (CustomSerializer.isCustom(encodedValue)) {
 472                                 // custom:TYPE_NAME:"content is String-encoded"
 473                                 String type = CustomSerializer.typeOf(encodedValue);
 474                                 if (customTypes.containsKey(type)) {
 475                                         // TODO: we should start with a stream
 476                                         InputStream streamEncodedValue = new ByteArrayInputStream(
 477                                                         encodedValue.getBytes("UTF-8"));
 478                                         try {
 479                                                 return customTypes.get(type).decode(streamEncodedValue);
 480                                         } finally {
 481                                                 streamEncodedValue.close();
 482                                         }
 483                                 }
 484                                 throw new IOException("Unknown custom type: " + type);
 485                         } else if (encodedValue.equals("NULL")
 486                                         || encodedValue.equals("null")) {
 487                                 return null;
 488                         } else if (encodedValue.endsWith("\"")) {
 489                                 return decodeString(encodedValue);
 490                         } else if (encodedValue.equals("true")) {
 491                                 return true;
 492                         } else if (encodedValue.equals("false")) {
 493                                 return false;
 494                         } else if (encodedValue.endsWith("b")) {
 495                                 return Byte.parseByte(cut);
 496                         } else if (encodedValue.endsWith("c")) {
 497                                 return decodeString(cut).charAt(0);
 498                         } else if (encodedValue.endsWith("s")) {
 499                                 return Short.parseShort(cut);
 500                         } else if (encodedValue.endsWith("L")) {
 501                                 return Long.parseLong(cut);
 502                         } else if (encodedValue.endsWith("F")) {
 503                                 return Float.parseFloat(cut);
 504                         } else if (encodedValue.endsWith("d")) {
 505                                 return Double.parseDouble(cut);
 506                         } else if (encodedValue.endsWith(";")) {
 507                                 return decodeEnum(encodedValue);
 508                         } else {
 509                                 return Integer.parseInt(encodedValue);
 510                         }
 511                 } catch (Exception e) {
 512                         if (e instanceof IOException) {
 513                                 throw (IOException) e;
 514                         }
 515                         throw new IOException(e.getMessage());
 516                 }
 517         }
 518
 519         /**
 520          * Write the given {@link String} into the given {@link OutputStream} in
 521          * UTF-8.
 522          *
 523          * @param out
 524          *            the {@link OutputStream}
 525          * @param data
 526          *            the data to write, cannot be NULL
 527          *
 528          * @throws IOException
 529          *             in case of I/O error
 530          */
 531         static void write(OutputStream out, Object data) throws IOException {
 532                 try {
 533                         out.write(data.toString().getBytes("UTF-8"));
 534                 } catch (UnsupportedEncodingException e) {
 535                         // A conforming JVM is required to support UTF-8
 536                         e.printStackTrace();
 537                 }
 538         }
 539
 540         /**
 541          * Return the corresponding class or throw an {@link Exception} if it
 542          * cannot.
 543          *
 544          * @param type
 545          *            the class name to look for
 546          *
 547          * @return the class (will never be NULL)
 548          *
 549          * @throws ClassNotFoundException
 550          *             if the class cannot be found
 551          * @throws NoSuchMethodException
 552          *             if the class cannot be created (usually because it or its
 553          *             enclosing class doesn't have an empty constructor)
 554          */
 555         static private Class<?> getClass(String type)
 556                         throws ClassNotFoundException, NoSuchMethodException {
 557                 Class<?> clazz = null;
 558                 try {
 559                         clazz = Class.forName(type);
 560                 } catch (ClassNotFoundException e) {
 561                         int pos = type.length();
 562                         pos = type.lastIndexOf(".", pos);
 563                         if (pos >= 0) {
 564                                 String parentType = type.substring(0, pos);
 565                                 String nestedType = type.substring(pos + 1);
 566                                 Class<?> javaParent = null;
 567                                 try {
 568                                         javaParent = getClass(parentType);
 569                                         parentType = javaParent.getName();
 570                                         clazz = Class.forName(parentType + "$" + nestedType);
 571                                 } catch (Exception ee) {
 572                                 }
 573
 574                                 if (javaParent == null) {
 575                                         throw new NoSuchMethodException(
 576                                                         "Class not found: "
 577                                                                         + type
 578                                                                         + " (the enclosing class cannot be created: maybe it doesn't have an empty constructor?)");
 579                                 }
 580                         }
 581                 }
 582
 583                 if (clazz == null) {
 584                         throw new ClassNotFoundException("Class not found: " + type);
 585                 }
 586
 587                 return clazz;
 588         }
 589
 590         @SuppressWarnings({ "unchecked", "rawtypes" })
 591         static private Enum<?> decodeEnum(String escaped) {
 592                 // escaped: be.xxx.EnumType.VALUE;
 593                 int pos = escaped.lastIndexOf(".");
 594                 String type = escaped.substring(0, pos);
 595                 String name = escaped.substring(pos + 1, escaped.length() - 1);
 596
 597                 try {
 598                         return Enum.valueOf((Class<Enum>) getClass(type), name);
 599                 } catch (Exception e) {
 600                         throw new UnknownFormatConversionException("Unknown enum: <" + type
 601                                         + "> " + name);
 602                 }
 603         }
 604
 605         // aa bb -> "aa\tbb"
 606         static void encodeString(OutputStream out, String raw) throws IOException {
 607                 out.write('\"');
 608                 // TODO !! utf-8 required
 609                 for (char car : raw.toCharArray()) {
 610                         encodeString(out, car);
 611                 }
 612                 out.write('\"');
 613         }
 614
 615         // aa bb -> "aa\tbb"
 616         static void encodeString(OutputStream out, InputStream raw)
 617                         throws IOException {
 618                 out.write('\"');
 619                 byte buffer[] = new byte[4096];
 620                 for (int len = 0; (len = raw.read(buffer)) > 0;) {
 621                         for (int i = 0; i < len; i++) {
 622                                 // TODO: not 100% correct, look up howto for UTF-8
 623                                 encodeString(out, (char) buffer[i]);
 624                         }
 625                 }
 626                 out.write('\"');
 627         }
 628
 629         // for encode string, NOT to encode a char by itself!
 630         static void encodeString(OutputStream out, char raw) throws IOException {
 631                 switch (raw) {
 632                 case '\\':
 633                         out.write('\\');
 634                         out.write('\\');
 635                         break;
 636                 case '\r':
 637                         out.write('\\');
 638                         out.write('r');
 639                         break;
 640                 case '\n':
 641                         out.write('\\');
 642                         out.write('n');
 643                         break;
 644                 case '"':
 645                         out.write('\\');
 646                         out.write('\"');
 647                         break;
 648                 default:
 649                         out.write(raw);
 650                         break;
 651                 }
 652         }
 653
 654         // "aa\tbb" -> aa bb
 655         static String decodeString(String escaped) {
 656                 StringBuilder builder = new StringBuilder();
 657
 658                 boolean escaping = false;
 659                 for (char car : escaped.toCharArray()) {
 660                         if (!escaping) {
 661                                 if (car == '\\') {
 662                                         escaping = true;
 663                                 } else {
 664                                         builder.append(car);
 665                                 }
 666                         } else {
 667                                 switch (car) {
 668                                 case '\\':
 669                                         builder.append('\\');
 670                                         break;
 671                                 case 'r':
 672                                         builder.append('\r');
 673                                         break;
 674                                 case 'n':
 675                                         builder.append('\n');
 676                                         break;
 677                                 case '"':
 678                                         builder.append('"');
 679                                         break;
 680                                 }
 681                                 escaping = false;
 682                         }
 683                 }
 684
 685                 return builder.substring(1, builder.length() - 1);
 686         }
 687 }