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.StringUtils;
  23 import be.nikiroo.utils.streams.NextableInputStream;
  24 import be.nikiroo.utils.streams.NextableInputStreamStep;
  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
  67                                 // TODO: we use \n to separate, and b64 to un-\n
  68                                 // -- but we could use \\n ?
  69                                 String type = value.getClass().getCanonicalName();
  70                                 type = type.substring(0, type.length() - 2); // remove the []
  71
  72                                 write(out, type);
  73                                 write(out, "\r");
  74                                 try {
  75                                         for (int i = 0; true; i++) {
  76                                                 Object item = Array.get(value, i);
  77                                                 // encode it normally if direct value
  78                                                 if (!SerialUtils.encode(out, item)) {
  79                                                         try {
  80                                                                 // TODO: bad escaping?
  81                                                                 write(out, "B64:");
  82                                                                 OutputStream bout = StringUtils.base64(out,
  83                                                                                 false, false);
  84                                                                 new Exporter(bout).append(item);
  85                                                         } catch (NotSerializableException e) {
  86                                                                 throw new UnknownFormatConversionException(e
  87                                                                                 .getMessage());
  88                                                         }
  89                                                 }
  90                                                 write(out, "\r");
  91                                         }
  92                                 } catch (ArrayIndexOutOfBoundsException e) {
  93                                         // Done.
  94                                 }
  95                         }
  96
  97                         @Override
  98                         protected Object fromStream(InputStream in) throws IOException {
  99                                 NextableInputStream stream = new NextableInputStream(in,
 100                                                 new NextableInputStreamStep('\r'));
 101
 102                                 try {
 103                                         List<Object> list = new ArrayList<Object>();
 104                                         stream.next();
 105                                         String type = IOUtils.readSmallStream(stream);
 106
 107                                         while (stream.next()) {
 108                                                 Object value = new Importer().read(stream).getValue();
 109                                                 list.add(value);
 110                                         }
 111
 112                                         Object array = Array.newInstance(
 113                                                         SerialUtils.getClass(type), list.size());
 114                                         for (int i = 0; i < list.size(); i++) {
 115                                                 Array.set(array, i, list.get(i));
 116                                         }
 117
 118                                         return array;
 119                                 } catch (Exception e) {
 120                                         if (e instanceof IOException) {
 121                                                 throw (IOException) e;
 122                                         }
 123                                         throw new IOException(e.getMessage());
 124                                 }
 125                         }
 126
 127                         @Override
 128                         protected String getType() {
 129                                 return "[]";
 130                         }
 131                 });
 132
 133                 // URL:
 134                 customTypes.put("java.net.URL", new CustomSerializer() {
 135                         @Override
 136                         protected void toStream(OutputStream out, Object value)
 137                                         throws IOException {
 138                                 String val = "";
 139                                 if (value != null) {
 140                                         val = ((URL) value).toString();
 141                                 }
 142
 143                                 out.write(val.getBytes("UTF-8"));
 144                         }
 145
 146                         @Override
 147                         protected Object fromStream(InputStream in) throws IOException {
 148                                 String val = IOUtils.readSmallStream(in);
 149                                 if (!val.isEmpty()) {
 150                                         return new URL(val);
 151                                 }
 152
 153                                 return null;
 154                         }
 155
 156                         @Override
 157                         protected String getType() {
 158                                 return "java.net.URL";
 159                         }
 160                 });
 161
 162                 // Images (this is currently the only supported image type by default)
 163                 customTypes.put("be.nikiroo.utils.Image", new CustomSerializer() {
 164                         @Override
 165                         protected void toStream(OutputStream out, Object value)
 166                                         throws IOException {
 167                                 Image img = (Image) value;
 168                                 OutputStream encoded = StringUtils.base64(out, false, false);
 169                                 try {
 170                                         InputStream in = img.newInputStream();
 171                                         try {
 172                                                 IOUtils.write(in, encoded);
 173                                         } finally {
 174                                                 in.close();
 175                                         }
 176                                 } finally {
 177                                         encoded.close();
 178                                 }
 179                         }
 180
 181                         @Override
 182                         protected String getType() {
 183                                 return "be.nikiroo.utils.Image";
 184                         }
 185
 186                         @Override
 187                         protected Object fromStream(InputStream in) throws IOException {
 188                                 try {
 189                                         return new Image(in);
 190                                 } catch (IOException e) {
 191                                         throw new UnknownFormatConversionException(e.getMessage());
 192                                 }
 193                         }
 194                 });
 195         }
 196
 197         /**
 198          * Create an empty object of the given type.
 199          *
 200          * @param type
 201          *            the object type (its class name)
 202          *
 203          * @return the new object
 204          *
 205          * @throws ClassNotFoundException
 206          *             if the class cannot be found
 207          * @throws NoSuchMethodException
 208          *             if the given class is not compatible with this code
 209          */
 210         public static Object createObject(String type)
 211                         throws ClassNotFoundException, NoSuchMethodException {
 212
 213                 String desc = null;
 214                 try {
 215                         Class<?> clazz = getClass(type);
 216                         String className = clazz.getName();
 217                         List<Object> args = new ArrayList<Object>();
 218                         List<Class<?>> classes = new ArrayList<Class<?>>();
 219                         Constructor<?> ctor = null;
 220                         if (className.contains("$")) {
 221                                 for (String parentName = className.substring(0,
 222                                                 className.lastIndexOf('$'));; parentName = parentName
 223                                                 .substring(0, parentName.lastIndexOf('$'))) {
 224                                         Object parent = createObject(parentName);
 225                                         args.add(parent);
 226                                         classes.add(parent.getClass());
 227
 228                                         if (!parentName.contains("$")) {
 229                                                 break;
 230                                         }
 231                                 }
 232
 233                                 // Better error description in case there is no empty
 234                                 // constructor:
 235                                 desc = "";
 236                                 String end = "";
 237                                 for (Class<?> parent = clazz; parent != null
 238                                                 && !parent.equals(Object.class); parent = parent
 239                                                 .getSuperclass()) {
 240                                         if (!desc.isEmpty()) {
 241                                                 desc += " [:";
 242                                                 end += "]";
 243                                         }
 244                                         desc += parent;
 245                                 }
 246                                 desc += end;
 247                                 //
 248
 249                                 try {
 250                                         ctor = clazz.getDeclaredConstructor(classes
 251                                                         .toArray(new Class[] {}));
 252                                 } catch (NoSuchMethodException nsme) {
 253                                         // TODO: it seems we do not always need a parameter for each
 254                                         // level, so we currently try "ALL" levels or "FIRST" level
 255                                         // only -> we should check the actual rule and use it
 256                                         ctor = clazz.getDeclaredConstructor(classes.get(0));
 257                                         Object firstParent = args.get(0);
 258                                         args.clear();
 259                                         args.add(firstParent);
 260                                 }
 261                                 desc = null;
 262                         } else {
 263                                 ctor = clazz.getDeclaredConstructor();
 264                         }
 265
 266                         ctor.setAccessible(true);
 267                         return ctor.newInstance(args.toArray());
 268                 } catch (ClassNotFoundException e) {
 269                         throw e;
 270                 } catch (NoSuchMethodException e) {
 271                         if (desc != null) {
 272                                 throw new NoSuchMethodException("Empty constructor not found: "
 273                                                 + desc);
 274                         }
 275                         throw e;
 276                 } catch (Exception e) {
 277                         throw new NoSuchMethodException("Cannot instantiate: " + type);
 278                 }
 279         }
 280
 281         /**
 282          * Insert a custom serialiser that will take precedence over the default one
 283          * or the target class.
 284          *
 285          * @param serializer
 286          *            the custom serialiser
 287          */
 288         static public void addCustomSerializer(CustomSerializer serializer) {
 289                 customTypes.put(serializer.getType(), serializer);
 290         }
 291
 292         /**
 293          * Serialise the given object into this {@link OutputStream}.
 294          * <p>
 295          * <b>Important: </b>If the operation fails (with a
 296          * {@link NotSerializableException}), the {@link StringBuilder} will be
 297          * corrupted (will contain bad, most probably not importable data).
 298          *
 299          * @param out
 300          *            the output {@link OutputStream} to serialise to
 301          * @param o
 302          *            the object to serialise
 303          * @param map
 304          *            the map of already serialised objects (if the given object or
 305          *            one of its descendant is already present in it, only an ID
 306          *            will be serialised)
 307          *
 308          * @throws NotSerializableException
 309          *             if the object cannot be serialised (in this case, the
 310          *             {@link StringBuilder} can contain bad, most probably not
 311          *             importable data)
 312          * @throws IOException
 313          *             in case of I/O errors
 314          */
 315         static void append(OutputStream out, Object o, Map<Integer, Object> map)
 316                         throws NotSerializableException, IOException {
 317
 318                 Field[] fields = new Field[] {};
 319                 String type = "";
 320                 String id = "NULL";
 321
 322                 if (o != null) {
 323                         int hash = System.identityHashCode(o);
 324                         fields = o.getClass().getDeclaredFields();
 325                         type = o.getClass().getCanonicalName();
 326                         if (type == null) {
 327                                 // Anonymous inner classes support
 328                                 type = o.getClass().getName();
 329                         }
 330                         id = Integer.toString(hash);
 331                         if (map.containsKey(hash)) {
 332                                 fields = new Field[] {};
 333                         } else {
 334                                 map.put(hash, o);
 335                         }
 336                 }
 337
 338                 write(out, "{\nREF ");
 339                 write(out, type);
 340                 write(out, "@");
 341                 write(out, id);
 342                 write(out, ":");
 343
 344                 if (!encode(out, o)) { // check if direct value
 345                         try {
 346                                 for (Field field : fields) {
 347                                         field.setAccessible(true);
 348
 349                                         if (field.getName().startsWith("this$")
 350                                                         || field.isSynthetic()
 351                                                         || (field.getModifiers() & Modifier.STATIC) == Modifier.STATIC) {
 352                                                 // Do not keep this links of nested classes
 353                                                 // Do not keep synthetic fields
 354                                                 // Do not keep final fields
 355                                                 continue;
 356                                         }
 357
 358                                         write(out, "\n");
 359                                         write(out, field.getName());
 360                                         write(out, ":");
 361
 362                                         Object value = field.get(o);
 363
 364                                         if (!encode(out, value)) {
 365                                                 write(out, "\n");
 366                                                 append(out, value, map);
 367                                         }
 368                                 }
 369                         } catch (IllegalArgumentException e) {
 370                                 e.printStackTrace(); // should not happen (see
 371                                                                                 // setAccessible)
 372                         } catch (IllegalAccessException e) {
 373                                 e.printStackTrace(); // should not happen (see
 374                                                                                 // setAccessible)
 375                         }
 376                 }
 377                 write(out, "\n}");
 378         }
 379
 380         /**
 381          * Encode the object into the given {@link OutputStream} if possible and if
 382          * supported.
 383          * <p>
 384          * A supported object in this context means an object we can directly
 385          * encode, like an Integer or a String. Custom objects and arrays are also
 386          * considered supported, but <b>compound objects are not supported here</b>.
 387          * <p>
 388          * For compound objects, you should use {@link Exporter}.
 389          *
 390          * @param out
 391          *            the {@link OutputStream} to append to
 392          * @param value
 393          *            the object to encode (can be NULL, which will be encoded)
 394          *
 395          * @return TRUE if success, FALSE if not (the content of the
 396          *         {@link OutputStream} won't be changed in case of failure)
 397          *
 398          * @throws IOException
 399          *             in case of I/O error
 400          */
 401         static boolean encode(OutputStream out, Object value) throws IOException {
 402                 if (value == null) {
 403                         write(out, "NULL");
 404                 } else if (value.getClass().getSimpleName().endsWith("[]")) {
 405                         // Simple name does support [] suffix and do not return NULL for
 406                         // inner anonymous classes
 407                         customTypes.get("[]").encode(out, value);
 408                 } else if (customTypes.containsKey(value.getClass().getCanonicalName())) {
 409                         customTypes.get(value.getClass().getCanonicalName())//
 410                                         .encode(out, value);
 411                 } else if (value instanceof String) {
 412                         encodeString(out, (String) value);
 413                 } else if (value instanceof Boolean) {
 414                         write(out, value);
 415                 } else if (value instanceof Byte) {
 416                         write(out, value);
 417                         write(out, "b");
 418                 } else if (value instanceof Character) {
 419                         encodeString(out, "" + value);
 420                         write(out, "c");
 421                 } else if (value instanceof Short) {
 422                         write(out, value);
 423                         write(out, "s");
 424                 } else if (value instanceof Integer) {
 425                         write(out, value);
 426                 } else if (value instanceof Long) {
 427                         write(out, value);
 428                         write(out, "L");
 429                 } else if (value instanceof Float) {
 430                         write(out, value);
 431                         write(out, "F");
 432                 } else if (value instanceof Double) {
 433                         write(out, value);
 434                         write(out, "d");
 435                 } else if (value instanceof Enum) {
 436                         String type = value.getClass().getCanonicalName();
 437                         write(out, type);
 438                         write(out, ".");
 439                         write(out, ((Enum<?>) value).name());
 440                         write(out, ";");
 441                 } else {
 442                         return false;
 443                 }
 444
 445                 return true;
 446         }
 447
 448         /**
 449          * Decode the data into an equivalent supported source object.
 450          * <p>
 451          * A supported object in this context means an object we can directly
 452          * encode, like an Integer or a String. Custom objects and arrays are also
 453          * considered supported, but <b>compound objects are not supported here</b>.
 454          * <p>
 455          * For compound objects, you should use {@link Importer}.
 456          *
 457          * @param encodedValue
 458          *            the encoded data, cannot be NULL
 459          *
 460          * @return the object (can be NULL for NULL encoded values)
 461          *
 462          * @throws IOException
 463          *             if the content cannot be converted
 464          */
 465         static Object decode(String encodedValue) throws IOException {
 466                 try {
 467                         String cut = "";
 468                         if (encodedValue.length() > 1) {
 469                                 cut = encodedValue.substring(0, encodedValue.length() - 1);
 470                         }
 471
 472                         if (CustomSerializer.isCustom(encodedValue)) {
 473                                 // custom:TYPE_NAME:"content is String-encoded"
 474                                 String type = CustomSerializer.typeOf(encodedValue);
 475                                 if (customTypes.containsKey(type)) {
 476                                         // TODO: we should start with a stream
 477                                         InputStream streamEncodedValue = new ByteArrayInputStream(
 478                                                         encodedValue.getBytes("UTF-8"));
 479                                         try {
 480                                                 return customTypes.get(type).decode(streamEncodedValue);
 481                                         } finally {
 482                                                 streamEncodedValue.close();
 483                                         }
 484                                 }
 485                                 throw new IOException("Unknown custom type: " + type);
 486                         } else if (encodedValue.equals("NULL")
 487                                         || encodedValue.equals("null")) {
 488                                 return null;
 489                         } else if (encodedValue.endsWith("\"")) {
 490                                 return decodeString(encodedValue);
 491                         } else if (encodedValue.equals("true")) {
 492                                 return true;
 493                         } else if (encodedValue.equals("false")) {
 494                                 return false;
 495                         } else if (encodedValue.endsWith("b")) {
 496                                 return Byte.parseByte(cut);
 497                         } else if (encodedValue.endsWith("c")) {
 498                                 return decodeString(cut).charAt(0);
 499                         } else if (encodedValue.endsWith("s")) {
 500                                 return Short.parseShort(cut);
 501                         } else if (encodedValue.endsWith("L")) {
 502                                 return Long.parseLong(cut);
 503                         } else if (encodedValue.endsWith("F")) {
 504                                 return Float.parseFloat(cut);
 505                         } else if (encodedValue.endsWith("d")) {
 506                                 return Double.parseDouble(cut);
 507                         } else if (encodedValue.endsWith(";")) {
 508                                 return decodeEnum(encodedValue);
 509                         } else {
 510                                 return Integer.parseInt(encodedValue);
 511                         }
 512                 } catch (Exception e) {
 513                         if (e instanceof IOException) {
 514                                 throw (IOException) e;
 515                         }
 516                         throw new IOException(e.getMessage());
 517                 }
 518         }
 519
 520         /**
 521          * Write the given {@link String} into the given {@link OutputStream} in
 522          * UTF-8.
 523          *
 524          * @param out
 525          *            the {@link OutputStream}
 526          * @param data
 527          *            the data to write, cannot be NULL
 528          *
 529          * @throws IOException
 530          *             in case of I/O error
 531          */
 532         static void write(OutputStream out, Object data) throws IOException {
 533                 try {
 534                         out.write(data.toString().getBytes("UTF-8"));
 535                 } catch (UnsupportedEncodingException e) {
 536                         // A conforming JVM is required to support UTF-8
 537                         e.printStackTrace();
 538                 }
 539         }
 540
 541         /**
 542          * Return the corresponding class or throw an {@link Exception} if it
 543          * cannot.
 544          *
 545          * @param type
 546          *            the class name to look for
 547          *
 548          * @return the class (will never be NULL)
 549          *
 550          * @throws ClassNotFoundException
 551          *             if the class cannot be found
 552          * @throws NoSuchMethodException
 553          *             if the class cannot be created (usually because it or its
 554          *             enclosing class doesn't have an empty constructor)
 555          */
 556         static private Class<?> getClass(String type)
 557                         throws ClassNotFoundException, NoSuchMethodException {
 558                 Class<?> clazz = null;
 559                 try {
 560                         clazz = Class.forName(type);
 561                 } catch (ClassNotFoundException e) {
 562                         int pos = type.length();
 563                         pos = type.lastIndexOf(".", pos);
 564                         if (pos >= 0) {
 565                                 String parentType = type.substring(0, pos);
 566                                 String nestedType = type.substring(pos + 1);
 567                                 Class<?> javaParent = null;
 568                                 try {
 569                                         javaParent = getClass(parentType);
 570                                         parentType = javaParent.getName();
 571                                         clazz = Class.forName(parentType + "$" + nestedType);
 572                                 } catch (Exception ee) {
 573                                 }
 574
 575                                 if (javaParent == null) {
 576                                         throw new NoSuchMethodException(
 577                                                         "Class not found: "
 578                                                                         + type
 579                                                                         + " (the enclosing class cannot be created: maybe it doesn't have an empty constructor?)");
 580                                 }
 581                         }
 582                 }
 583
 584                 if (clazz == null) {
 585                         throw new ClassNotFoundException("Class not found: " + type);
 586                 }
 587
 588                 return clazz;
 589         }
 590
 591         @SuppressWarnings({ "unchecked", "rawtypes" })
 592         static private Enum<?> decodeEnum(String escaped) {
 593                 // escaped: be.xxx.EnumType.VALUE;
 594                 int pos = escaped.lastIndexOf(".");
 595                 String type = escaped.substring(0, pos);
 596                 String name = escaped.substring(pos + 1, escaped.length() - 1);
 597
 598                 try {
 599                         return Enum.valueOf((Class<Enum>) getClass(type), name);
 600                 } catch (Exception e) {
 601                         throw new UnknownFormatConversionException("Unknown enum: <" + type
 602                                         + "> " + name);
 603                 }
 604         }
 605
 606         // aa bb -> "aa\tbb"
 607         static void encodeString(OutputStream out, String raw) throws IOException {
 608                 // TODO: not. efficient.
 609                 out.write('\"');
 610                 // TODO !! utf-8 required
 611                 for (char car : raw.toCharArray()) {
 612                         encodeString(out, car);
 613                 }
 614                 out.write('\"');
 615         }
 616
 617         // aa bb -> "aa\tbb"
 618         static void encodeString(OutputStream out, InputStream raw)
 619                         throws IOException {
 620                 out.write('\"');
 621                 byte buffer[] = new byte[4096];
 622                 for (int len = 0; (len = raw.read(buffer)) > 0;) {
 623                         for (int i = 0; i < len; i++) {
 624                                 // TODO: not 100% correct, look up howto for UTF-8
 625                                 encodeString(out, (char) buffer[i]);
 626                         }
 627                 }
 628                 out.write('\"');
 629         }
 630
 631         // for encode string, NOT to encode a char by itself!
 632         static void encodeString(OutputStream out, char raw) throws IOException {
 633                 switch (raw) {
 634                 case '\\':
 635                         out.write('\\');
 636                         out.write('\\');
 637                         break;
 638                 case '\r':
 639                         out.write('\\');
 640                         out.write('r');
 641                         break;
 642                 case '\n':
 643                         out.write('\\');
 644                         out.write('n');
 645                         break;
 646                 case '"':
 647                         out.write('\\');
 648                         out.write('\"');
 649                         break;
 650                 default:
 651                         out.write(raw);
 652                         break;
 653                 }
 654         }
 655
 656         // "aa\tbb" -> aa bb
 657         static String decodeString(String escaped) {
 658                 StringBuilder builder = new StringBuilder();
 659
 660                 boolean escaping = false;
 661                 for (char car : escaped.toCharArray()) {
 662                         if (!escaping) {
 663                                 if (car == '\\') {
 664                                         escaping = true;
 665                                 } else {
 666                                         builder.append(car);
 667                                 }
 668                         } else {
 669                                 switch (car) {
 670                                 case '\\':
 671                                         builder.append('\\');
 672                                         break;
 673                                 case 'r':
 674                                         builder.append('\r');
 675                                         break;
 676                                 case 'n':
 677                                         builder.append('\n');
 678                                         break;
 679                                 case '"':
 680                                         builder.append('"');
 681                                         break;
 682                                 }
 683                                 escaping = false;
 684                         }
 685                 }
 686
 687                 return builder.substring(1, builder.length() - 1);
 688         }
 689 }