ScriptObjectMirror.java revision 1210:13b4d61fac98
1/* 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package jdk.nashorn.api.scripting; 27 28import java.nio.ByteBuffer; 29import java.security.AccessControlContext; 30import java.security.AccessController; 31import java.security.Permissions; 32import java.security.PrivilegedAction; 33import java.security.ProtectionDomain; 34import java.util.AbstractMap; 35import java.util.ArrayList; 36import java.util.Collection; 37import java.util.Collections; 38import java.util.Iterator; 39import java.util.LinkedHashSet; 40import java.util.List; 41import java.util.Map; 42import java.util.Objects; 43import java.util.Set; 44import java.util.concurrent.Callable; 45import javax.script.Bindings; 46import jdk.nashorn.internal.objects.Global; 47import jdk.nashorn.internal.runtime.ConsString; 48import jdk.nashorn.internal.runtime.Context; 49import jdk.nashorn.internal.runtime.ECMAException; 50import jdk.nashorn.internal.runtime.JSType; 51import jdk.nashorn.internal.runtime.ScriptFunction; 52import jdk.nashorn.internal.runtime.ScriptObject; 53import jdk.nashorn.internal.runtime.ScriptRuntime; 54import jdk.nashorn.internal.runtime.arrays.ArrayData; 55import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor; 56 57/** 58 * Mirror object that wraps a given Nashorn Script object. 59 * 60 * @since 1.8u40 61 */ 62@jdk.Exported 63public final class ScriptObjectMirror extends AbstractJSObject implements Bindings { 64 private static AccessControlContext getContextAccCtxt() { 65 final Permissions perms = new Permissions(); 66 perms.add(new RuntimePermission(Context.NASHORN_GET_CONTEXT)); 67 return new AccessControlContext(new ProtectionDomain[] { new ProtectionDomain(null, perms) }); 68 } 69 70 private static final AccessControlContext GET_CONTEXT_ACC_CTXT = getContextAccCtxt(); 71 72 private final ScriptObject sobj; 73 private final Global global; 74 private final boolean strict; 75 76 @Override 77 public boolean equals(final Object other) { 78 if (other instanceof ScriptObjectMirror) { 79 return sobj.equals(((ScriptObjectMirror)other).sobj); 80 } 81 82 return false; 83 } 84 85 @Override 86 public int hashCode() { 87 return sobj.hashCode(); 88 } 89 90 @Override 91 public String toString() { 92 return inGlobal(new Callable<String>() { 93 @Override 94 public String call() { 95 return ScriptRuntime.safeToString(sobj); 96 } 97 }); 98 } 99 100 // JSObject methods 101 102 @Override 103 public Object call(final Object thiz, final Object... args) { 104 final Global oldGlobal = Context.getGlobal(); 105 final boolean globalChanged = (oldGlobal != global); 106 107 try { 108 if (globalChanged) { 109 Context.setGlobal(global); 110 } 111 112 if (sobj instanceof ScriptFunction) { 113 final Object[] modArgs = globalChanged? wrapArray(args, oldGlobal) : args; 114 final Object self = globalChanged? wrap(thiz, oldGlobal) : thiz; 115 return wrap(ScriptRuntime.apply((ScriptFunction)sobj, unwrap(self, global), unwrapArray(modArgs, global)), global); 116 } 117 118 throw new RuntimeException("not a function: " + toString()); 119 } catch (final NashornException ne) { 120 throw ne.initEcmaError(global); 121 } catch (final RuntimeException | Error e) { 122 throw e; 123 } catch (final Throwable t) { 124 throw new RuntimeException(t); 125 } finally { 126 if (globalChanged) { 127 Context.setGlobal(oldGlobal); 128 } 129 } 130 } 131 132 @Override 133 public Object newObject(final Object... args) { 134 final Global oldGlobal = Context.getGlobal(); 135 final boolean globalChanged = (oldGlobal != global); 136 137 try { 138 if (globalChanged) { 139 Context.setGlobal(global); 140 } 141 142 if (sobj instanceof ScriptFunction) { 143 final Object[] modArgs = globalChanged? wrapArray(args, oldGlobal) : args; 144 return wrap(ScriptRuntime.construct((ScriptFunction)sobj, unwrapArray(modArgs, global)), global); 145 } 146 147 throw new RuntimeException("not a constructor: " + toString()); 148 } catch (final NashornException ne) { 149 throw ne.initEcmaError(global); 150 } catch (final RuntimeException | Error e) { 151 throw e; 152 } catch (final Throwable t) { 153 throw new RuntimeException(t); 154 } finally { 155 if (globalChanged) { 156 Context.setGlobal(oldGlobal); 157 } 158 } 159 } 160 161 @Override 162 public Object eval(final String s) { 163 return inGlobal(new Callable<Object>() { 164 @Override 165 public Object call() { 166 final Context context = AccessController.doPrivileged( 167 new PrivilegedAction<Context>() { 168 @Override 169 public Context run() { 170 return Context.getContext(); 171 } 172 }, GET_CONTEXT_ACC_CTXT); 173 return wrap(context.eval(global, s, sobj, null, false), global); 174 } 175 }); 176 } 177 178 /** 179 * Call member function 180 * @param functionName function name 181 * @param args arguments 182 * @return return value of function 183 */ 184 public Object callMember(final String functionName, final Object... args) { 185 Objects.requireNonNull(functionName); 186 final Global oldGlobal = Context.getGlobal(); 187 final boolean globalChanged = (oldGlobal != global); 188 189 try { 190 if (globalChanged) { 191 Context.setGlobal(global); 192 } 193 194 final Object val = sobj.get(functionName); 195 if (val instanceof ScriptFunction) { 196 final Object[] modArgs = globalChanged? wrapArray(args, oldGlobal) : args; 197 return wrap(ScriptRuntime.apply((ScriptFunction)val, sobj, unwrapArray(modArgs, global)), global); 198 } else if (val instanceof JSObject && ((JSObject)val).isFunction()) { 199 return ((JSObject)val).call(sobj, args); 200 } 201 202 throw new NoSuchMethodException("No such function " + functionName); 203 } catch (final NashornException ne) { 204 throw ne.initEcmaError(global); 205 } catch (final RuntimeException | Error e) { 206 throw e; 207 } catch (final Throwable t) { 208 throw new RuntimeException(t); 209 } finally { 210 if (globalChanged) { 211 Context.setGlobal(oldGlobal); 212 } 213 } 214 } 215 216 @Override 217 public Object getMember(final String name) { 218 Objects.requireNonNull(name); 219 return inGlobal(new Callable<Object>() { 220 @Override public Object call() { 221 return wrap(sobj.get(name), global); 222 } 223 }); 224 } 225 226 @Override 227 public Object getSlot(final int index) { 228 return inGlobal(new Callable<Object>() { 229 @Override public Object call() { 230 return wrap(sobj.get(index), global); 231 } 232 }); 233 } 234 235 @Override 236 public boolean hasMember(final String name) { 237 Objects.requireNonNull(name); 238 return inGlobal(new Callable<Boolean>() { 239 @Override public Boolean call() { 240 return sobj.has(name); 241 } 242 }); 243 } 244 245 @Override 246 public boolean hasSlot(final int slot) { 247 return inGlobal(new Callable<Boolean>() { 248 @Override public Boolean call() { 249 return sobj.has(slot); 250 } 251 }); 252 } 253 254 @Override 255 public void removeMember(final String name) { 256 Objects.requireNonNull(name); 257 remove(name); 258 } 259 260 @Override 261 public void setMember(final String name, final Object value) { 262 Objects.requireNonNull(name); 263 put(name, value); 264 } 265 266 @Override 267 public void setSlot(final int index, final Object value) { 268 inGlobal(new Callable<Void>() { 269 @Override public Void call() { 270 sobj.set(index, unwrap(value, global), getCallSiteFlags()); 271 return null; 272 } 273 }); 274 } 275 276 /** 277 * Nashorn extension: setIndexedPropertiesToExternalArrayData. 278 * set indexed properties be exposed from a given nio ByteBuffer. 279 * 280 * @param buf external buffer - should be a nio ByteBuffer 281 */ 282 public void setIndexedPropertiesToExternalArrayData(final ByteBuffer buf) { 283 inGlobal(new Callable<Void>() { 284 @Override public Void call() { 285 sobj.setArray(ArrayData.allocate(buf)); 286 return null; 287 } 288 }); 289 } 290 291 292 @Override 293 public boolean isInstance(final Object obj) { 294 if (! (obj instanceof ScriptObjectMirror)) { 295 return false; 296 } 297 298 final ScriptObjectMirror instance = (ScriptObjectMirror)obj; 299 // if not belongs to my global scope, return false 300 if (global != instance.global) { 301 return false; 302 } 303 304 return inGlobal(new Callable<Boolean>() { 305 @Override public Boolean call() { 306 return sobj.isInstance(instance.sobj); 307 } 308 }); 309 } 310 311 @Override 312 public String getClassName() { 313 return sobj.getClassName(); 314 } 315 316 @Override 317 public boolean isFunction() { 318 return sobj instanceof ScriptFunction; 319 } 320 321 @Override 322 public boolean isStrictFunction() { 323 return isFunction() && ((ScriptFunction)sobj).isStrict(); 324 } 325 326 @Override 327 public boolean isArray() { 328 return sobj.isArray(); 329 } 330 331 // javax.script.Bindings methods 332 333 @Override 334 public void clear() { 335 inGlobal(new Callable<Object>() { 336 @Override public Object call() { 337 sobj.clear(strict); 338 return null; 339 } 340 }); 341 } 342 343 @Override 344 public boolean containsKey(final Object key) { 345 checkKey(key); 346 return inGlobal(new Callable<Boolean>() { 347 @Override public Boolean call() { 348 return sobj.containsKey(key); 349 } 350 }); 351 } 352 353 @Override 354 public boolean containsValue(final Object value) { 355 return inGlobal(new Callable<Boolean>() { 356 @Override public Boolean call() { 357 return sobj.containsValue(unwrap(value, global)); 358 } 359 }); 360 } 361 362 @Override 363 public Set<Map.Entry<String, Object>> entrySet() { 364 return inGlobal(new Callable<Set<Map.Entry<String, Object>>>() { 365 @Override public Set<Map.Entry<String, Object>> call() { 366 final Iterator<String> iter = sobj.propertyIterator(); 367 final Set<Map.Entry<String, Object>> entries = new LinkedHashSet<>(); 368 369 while (iter.hasNext()) { 370 final String key = iter.next(); 371 final Object value = translateUndefined(wrap(sobj.get(key), global)); 372 entries.add(new AbstractMap.SimpleImmutableEntry<>(key, value)); 373 } 374 375 return Collections.unmodifiableSet(entries); 376 } 377 }); 378 } 379 380 @Override 381 public Object get(final Object key) { 382 checkKey(key); 383 return inGlobal(new Callable<Object>() { 384 @Override public Object call() { 385 return translateUndefined(wrap(sobj.get(key), global)); 386 } 387 }); 388 } 389 390 @Override 391 public boolean isEmpty() { 392 return inGlobal(new Callable<Boolean>() { 393 @Override public Boolean call() { 394 return sobj.isEmpty(); 395 } 396 }); 397 } 398 399 @Override 400 public Set<String> keySet() { 401 return inGlobal(new Callable<Set<String>>() { 402 @Override public Set<String> call() { 403 final Iterator<String> iter = sobj.propertyIterator(); 404 final Set<String> keySet = new LinkedHashSet<>(); 405 406 while (iter.hasNext()) { 407 keySet.add(iter.next()); 408 } 409 410 return Collections.unmodifiableSet(keySet); 411 } 412 }); 413 } 414 415 @Override 416 public Object put(final String key, final Object value) { 417 checkKey(key); 418 final ScriptObject oldGlobal = Context.getGlobal(); 419 final boolean globalChanged = (oldGlobal != global); 420 return inGlobal(new Callable<Object>() { 421 @Override public Object call() { 422 final Object modValue = globalChanged? wrap(value, oldGlobal) : value; 423 return translateUndefined(wrap(sobj.put(key, unwrap(modValue, global), strict), global)); 424 } 425 }); 426 } 427 428 @Override 429 public void putAll(final Map<? extends String, ? extends Object> map) { 430 Objects.requireNonNull(map, "map is null"); 431 final ScriptObject oldGlobal = Context.getGlobal(); 432 final boolean globalChanged = (oldGlobal != global); 433 inGlobal(new Callable<Object>() { 434 @Override public Object call() { 435 for (final Map.Entry<? extends String, ? extends Object> entry : map.entrySet()) { 436 final Object value = entry.getValue(); 437 final Object modValue = globalChanged? wrap(value, oldGlobal) : value; 438 final String key = entry.getKey(); 439 checkKey(key); 440 sobj.set(key, unwrap(modValue, global), getCallSiteFlags()); 441 } 442 return null; 443 } 444 }); 445 } 446 447 @Override 448 public Object remove(final Object key) { 449 checkKey(key); 450 return inGlobal(new Callable<Object>() { 451 @Override public Object call() { 452 return translateUndefined(wrap(sobj.remove(key, strict), global)); 453 } 454 }); 455 } 456 457 /** 458 * Delete a property from this object. 459 * 460 * @param key the property to be deleted 461 * 462 * @return if the delete was successful or not 463 */ 464 public boolean delete(final Object key) { 465 return inGlobal(new Callable<Boolean>() { 466 @Override public Boolean call() { 467 return sobj.delete(unwrap(key, global), strict); 468 } 469 }); 470 } 471 472 @Override 473 public int size() { 474 return inGlobal(new Callable<Integer>() { 475 @Override public Integer call() { 476 return sobj.size(); 477 } 478 }); 479 } 480 481 @Override 482 public Collection<Object> values() { 483 return inGlobal(new Callable<Collection<Object>>() { 484 @Override public Collection<Object> call() { 485 final List<Object> values = new ArrayList<>(size()); 486 final Iterator<Object> iter = sobj.valueIterator(); 487 488 while (iter.hasNext()) { 489 values.add(translateUndefined(wrap(iter.next(), global))); 490 } 491 492 return Collections.unmodifiableList(values); 493 } 494 }); 495 } 496 497 // Support for ECMAScript Object API on mirrors 498 499 /** 500 * Return the __proto__ of this object. 501 * @return __proto__ object. 502 */ 503 public Object getProto() { 504 return inGlobal(new Callable<Object>() { 505 @Override public Object call() { 506 return wrap(sobj.getProto(), global); 507 } 508 }); 509 } 510 511 /** 512 * Set the __proto__ of this object. 513 * @param proto new proto for this object 514 */ 515 public void setProto(final Object proto) { 516 inGlobal(new Callable<Void>() { 517 @Override public Void call() { 518 sobj.setPrototypeOf(unwrap(proto, global)); 519 return null; 520 } 521 }); 522 } 523 524 /** 525 * ECMA 8.12.1 [[GetOwnProperty]] (P) 526 * 527 * @param key property key 528 * 529 * @return Returns the Property Descriptor of the named own property of this 530 * object, or undefined if absent. 531 */ 532 public Object getOwnPropertyDescriptor(final String key) { 533 return inGlobal(new Callable<Object>() { 534 @Override public Object call() { 535 return wrap(sobj.getOwnPropertyDescriptor(key), global); 536 } 537 }); 538 } 539 540 /** 541 * return an array of own property keys associated with the object. 542 * 543 * @param all True if to include non-enumerable keys. 544 * @return Array of keys. 545 */ 546 public String[] getOwnKeys(final boolean all) { 547 return inGlobal(new Callable<String[]>() { 548 @Override public String[] call() { 549 return sobj.getOwnKeys(all); 550 } 551 }); 552 } 553 554 /** 555 * Flag this script object as non extensible 556 * 557 * @return the object after being made non extensible 558 */ 559 public ScriptObjectMirror preventExtensions() { 560 return inGlobal(new Callable<ScriptObjectMirror>() { 561 @Override public ScriptObjectMirror call() { 562 sobj.preventExtensions(); 563 return ScriptObjectMirror.this; 564 } 565 }); 566 } 567 568 /** 569 * Check if this script object is extensible 570 * @return true if extensible 571 */ 572 public boolean isExtensible() { 573 return inGlobal(new Callable<Boolean>() { 574 @Override public Boolean call() { 575 return sobj.isExtensible(); 576 } 577 }); 578 } 579 580 /** 581 * ECMAScript 15.2.3.8 - seal implementation 582 * @return the sealed script object 583 */ 584 public ScriptObjectMirror seal() { 585 return inGlobal(new Callable<ScriptObjectMirror>() { 586 @Override public ScriptObjectMirror call() { 587 sobj.seal(); 588 return ScriptObjectMirror.this; 589 } 590 }); 591 } 592 593 /** 594 * Check whether this script object is sealed 595 * @return true if sealed 596 */ 597 public boolean isSealed() { 598 return inGlobal(new Callable<Boolean>() { 599 @Override public Boolean call() { 600 return sobj.isSealed(); 601 } 602 }); 603 } 604 605 /** 606 * ECMA 15.2.39 - freeze implementation. Freeze this script object 607 * @return the frozen script object 608 */ 609 public ScriptObjectMirror freeze() { 610 return inGlobal(new Callable<ScriptObjectMirror>() { 611 @Override public ScriptObjectMirror call() { 612 sobj.freeze(); 613 return ScriptObjectMirror.this; 614 } 615 }); 616 } 617 618 /** 619 * Check whether this script object is frozen 620 * @return true if frozen 621 */ 622 public boolean isFrozen() { 623 return inGlobal(new Callable<Boolean>() { 624 @Override public Boolean call() { 625 return sobj.isFrozen(); 626 } 627 }); 628 } 629 630 /** 631 * Utility to check if given object is ECMAScript undefined value 632 * 633 * @param obj object to check 634 * @return true if 'obj' is ECMAScript undefined value 635 */ 636 public static boolean isUndefined(final Object obj) { 637 return obj == ScriptRuntime.UNDEFINED; 638 } 639 640 /** 641 * Utility to convert this script object to the given type. 642 * 643 * @param <T> destination type to convert to 644 * @param type destination type to convert to 645 * @return converted object 646 */ 647 public <T> T to(final Class<T> type) { 648 return inGlobal(new Callable<T>() { 649 @Override 650 public T call() { 651 return type.cast(ScriptUtils.convert(sobj, type)); 652 } 653 }); 654 } 655 656 /** 657 * Make a script object mirror on given object if needed. Also converts ConsString instances to Strings. 658 * 659 * @param obj object to be wrapped/converted 660 * @param homeGlobal global to which this object belongs. Not used for ConsStrings. 661 * @return wrapped/converted object 662 */ 663 public static Object wrap(final Object obj, final Object homeGlobal) { 664 if(obj instanceof ScriptObject) { 665 return homeGlobal instanceof Global ? new ScriptObjectMirror((ScriptObject)obj, (Global)homeGlobal) : obj; 666 } 667 if(obj instanceof ConsString) { 668 return obj.toString(); 669 } 670 return obj; 671 } 672 673 /** 674 * Unwrap a script object mirror if needed. 675 * 676 * @param obj object to be unwrapped 677 * @param homeGlobal global to which this object belongs 678 * @return unwrapped object 679 */ 680 public static Object unwrap(final Object obj, final Object homeGlobal) { 681 if (obj instanceof ScriptObjectMirror) { 682 final ScriptObjectMirror mirror = (ScriptObjectMirror)obj; 683 return (mirror.global == homeGlobal)? mirror.sobj : obj; 684 } 685 686 return obj; 687 } 688 689 /** 690 * Wrap an array of object to script object mirrors if needed. 691 * 692 * @param args array to be unwrapped 693 * @param homeGlobal global to which this object belongs 694 * @return wrapped array 695 */ 696 public static Object[] wrapArray(final Object[] args, final Object homeGlobal) { 697 if (args == null || args.length == 0) { 698 return args; 699 } 700 701 final Object[] newArgs = new Object[args.length]; 702 int index = 0; 703 for (final Object obj : args) { 704 newArgs[index] = wrap(obj, homeGlobal); 705 index++; 706 } 707 return newArgs; 708 } 709 710 /** 711 * Unwrap an array of script object mirrors if needed. 712 * 713 * @param args array to be unwrapped 714 * @param homeGlobal global to which this object belongs 715 * @return unwrapped array 716 */ 717 public static Object[] unwrapArray(final Object[] args, final Object homeGlobal) { 718 if (args == null || args.length == 0) { 719 return args; 720 } 721 722 final Object[] newArgs = new Object[args.length]; 723 int index = 0; 724 for (final Object obj : args) { 725 newArgs[index] = unwrap(obj, homeGlobal); 726 index++; 727 } 728 return newArgs; 729 } 730 731 /** 732 * Are the given objects mirrors to same underlying object? 733 * 734 * @param obj1 first object 735 * @param obj2 second object 736 * @return true if obj1 and obj2 are identical script objects or mirrors of it. 737 */ 738 public static boolean identical(final Object obj1, final Object obj2) { 739 final Object o1 = (obj1 instanceof ScriptObjectMirror)? 740 ((ScriptObjectMirror)obj1).sobj : obj1; 741 742 final Object o2 = (obj2 instanceof ScriptObjectMirror)? 743 ((ScriptObjectMirror)obj2).sobj : obj2; 744 745 return o1 == o2; 746 } 747 748 // package-privates below this. 749 750 ScriptObjectMirror(final ScriptObject sobj, final Global global) { 751 assert sobj != null : "ScriptObjectMirror on null!"; 752 assert global != null : "home Global is null"; 753 754 this.sobj = sobj; 755 this.global = global; 756 this.strict = global.isStrictContext(); 757 } 758 759 // accessors for script engine 760 ScriptObject getScriptObject() { 761 return sobj; 762 } 763 764 Global getHomeGlobal() { 765 return global; 766 } 767 768 static Object translateUndefined(final Object obj) { 769 return (obj == ScriptRuntime.UNDEFINED)? null : obj; 770 } 771 772 private int getCallSiteFlags() { 773 return strict ? NashornCallSiteDescriptor.CALLSITE_STRICT : 0; 774 } 775 776 // internals only below this. 777 private <V> V inGlobal(final Callable<V> callable) { 778 final Global oldGlobal = Context.getGlobal(); 779 final boolean globalChanged = (oldGlobal != global); 780 if (globalChanged) { 781 Context.setGlobal(global); 782 } 783 try { 784 return callable.call(); 785 } catch (final NashornException ne) { 786 throw ne.initEcmaError(global); 787 } catch (final RuntimeException e) { 788 throw e; 789 } catch (final Exception e) { 790 throw new AssertionError("Cannot happen", e); 791 } finally { 792 if (globalChanged) { 793 Context.setGlobal(oldGlobal); 794 } 795 } 796 } 797 798 /** 799 * Ensures the key is not null, empty string, or a non-String object. The contract of the {@link Bindings} 800 * interface requires that these are not accepted as keys. 801 * @param key the key to check 802 * @throws NullPointerException if key is null 803 * @throws ClassCastException if key is not a String 804 * @throws IllegalArgumentException if key is empty string 805 */ 806 private static void checkKey(final Object key) { 807 Objects.requireNonNull(key, "key can not be null"); 808 809 if (!(key instanceof String)) { 810 throw new ClassCastException("key should be a String. It is " + key.getClass().getName() + " instead."); 811 } else if (((String)key).length() == 0) { 812 throw new IllegalArgumentException("key can not be empty"); 813 } 814 } 815 816 @Override @Deprecated 817 public double toNumber() { 818 return inGlobal(new Callable<Double>() { 819 @Override public Double call() { 820 return JSType.toNumber(sobj); 821 } 822 }); 823 } 824 825 @Override 826 public Object getDefaultValue(final Class<?> hint) { 827 return inGlobal(new Callable<Object>() { 828 @Override public Object call() { 829 try { 830 return sobj.getDefaultValue(hint); 831 } catch (final ECMAException e) { 832 // We're catching ECMAException (likely TypeError), and translating it to 833 // UnsupportedOperationException. This in turn will be translated into TypeError of the 834 // caller's Global by JSType#toPrimitive(JSObject,Class) therefore ensuring that it's 835 // recognized as "instanceof TypeError" in the caller. 836 throw new UnsupportedOperationException(e.getMessage(), e); 837 } 838 } 839 }); 840 } 841} 842