-
Notifications
You must be signed in to change notification settings - Fork 4.3k
/
Gson.java
1382 lines (1309 loc) · 60.9 KB
/
Gson.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Copyright (C) 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.gson;
import com.google.gson.internal.ConstructorConstructor;
import com.google.gson.internal.Excluder;
import com.google.gson.internal.GsonBuildConfig;
import com.google.gson.internal.LazilyParsedNumber;
import com.google.gson.internal.Primitives;
import com.google.gson.internal.Streams;
import com.google.gson.internal.bind.ArrayTypeAdapter;
import com.google.gson.internal.bind.CollectionTypeAdapterFactory;
import com.google.gson.internal.bind.DateTypeAdapter;
import com.google.gson.internal.bind.JsonAdapterAnnotationTypeAdapterFactory;
import com.google.gson.internal.bind.JsonTreeReader;
import com.google.gson.internal.bind.JsonTreeWriter;
import com.google.gson.internal.bind.MapTypeAdapterFactory;
import com.google.gson.internal.bind.NumberTypeAdapter;
import com.google.gson.internal.bind.ObjectTypeAdapter;
import com.google.gson.internal.bind.ReflectiveTypeAdapterFactory;
import com.google.gson.internal.bind.SerializationDelegatingTypeAdapter;
import com.google.gson.internal.bind.TypeAdapters;
import com.google.gson.internal.sql.SqlTypesSupport;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;
import com.google.gson.stream.MalformedJsonException;
import java.io.EOFException;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.reflect.Type;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicLongArray;
/**
* This is the main class for using Gson. Gson is typically used by first constructing a
* Gson instance and then invoking {@link #toJson(Object)} or {@link #fromJson(String, Class)}
* methods on it. Gson instances are Thread-safe so you can reuse them freely across multiple
* threads.
*
* <p>You can create a Gson instance by invoking {@code new Gson()} if the default configuration
* is all you need. You can also use {@link GsonBuilder} to build a Gson instance with various
* configuration options such as versioning support, pretty printing, custom
* {@link JsonSerializer}s, {@link JsonDeserializer}s, and {@link InstanceCreator}s.</p>
*
* <p>Here is an example of how Gson is used for a simple Class:
*
* <pre>
* Gson gson = new Gson(); // Or use new GsonBuilder().create();
* MyType target = new MyType();
* String json = gson.toJson(target); // serializes target to JSON
* MyType target2 = gson.fromJson(json, MyType.class); // deserializes json into target2
* </pre>
*
* <p>If the type of the object that you are converting is a {@code ParameterizedType}
* (i.e. has at least one type argument, for example {@code List<MyType>}) then for
* deserialization you must use a {@code fromJson} method with {@link Type} or {@link TypeToken}
* parameter to specify the parameterized type. For serialization specifying a {@code Type}
* or {@code TypeToken} is optional, otherwise Gson will use the runtime type of the object.
* {@link TypeToken} is a class provided by Gson which helps creating parameterized types.
* Here is an example showing how this can be done:
* <pre>
* TypeToken<List<MyType>> listType = new TypeToken<List<MyType>>() {};
* List<MyType> target = new LinkedList<MyType>();
* target.add(new MyType(1, "abc"));
*
* Gson gson = new Gson();
* // For serialization you normally do not have to specify the type, Gson will use
* // the runtime type of the objects, however you can also specify it explicitly
* String json = gson.toJson(target, listType.getType());
*
* // But for deserialization you have to specify the type
* List<MyType> target2 = gson.fromJson(json, listType);
* </pre>
*
* <p>See the <a href="https://github.com/google/gson/blob/master/UserGuide.md">Gson User Guide</a>
* for a more complete set of examples.</p>
*
* <h2>Lenient JSON handling</h2>
* For legacy reasons most of the {@code Gson} methods allow JSON data which does not
* comply with the JSON specification, regardless of whether {@link GsonBuilder#setLenient()}
* is used or not. If this behavior is not desired, the following workarounds can be used:
*
* <h3>Serialization</h3>
* <ol>
* <li>Use {@link #getAdapter(Class)} to obtain the adapter for the type to be serialized
* <li>When using an existing {@code JsonWriter}, manually apply the writer settings of this
* {@code Gson} instance listed by {@link #newJsonWriter(Writer)}.<br>
* Otherwise, when not using an existing {@code JsonWriter}, use {@link #newJsonWriter(Writer)}
* to construct one.
* <li>Call {@link TypeAdapter#write(JsonWriter, Object)}
* </ol>
*
* <h3>Deserialization</h3>
* <ol>
* <li>Use {@link #getAdapter(Class)} to obtain the adapter for the type to be deserialized
* <li>When using an existing {@code JsonReader}, manually apply the reader settings of this
* {@code Gson} instance listed by {@link #newJsonReader(Reader)}.<br>
* Otherwise, when not using an existing {@code JsonReader}, use {@link #newJsonReader(Reader)}
* to construct one.
* <li>Call {@link TypeAdapter#read(JsonReader)}
* <li>Call {@link JsonReader#peek()} and verify that the result is {@link JsonToken#END_DOCUMENT}
* to make sure there is no trailing data
* </ol>
*
* @see TypeToken
*
* @author Inderjeet Singh
* @author Joel Leitch
* @author Jesse Wilson
*/
public final class Gson {
static final boolean DEFAULT_JSON_NON_EXECUTABLE = false;
static final boolean DEFAULT_LENIENT = false;
static final boolean DEFAULT_PRETTY_PRINT = false;
static final boolean DEFAULT_ESCAPE_HTML = true;
static final boolean DEFAULT_SERIALIZE_NULLS = false;
static final boolean DEFAULT_COMPLEX_MAP_KEYS = false;
static final boolean DEFAULT_SPECIALIZE_FLOAT_VALUES = false;
static final boolean DEFAULT_USE_JDK_UNSAFE = true;
static final String DEFAULT_DATE_PATTERN = null;
static final FieldNamingStrategy DEFAULT_FIELD_NAMING_STRATEGY = FieldNamingPolicy.IDENTITY;
static final ToNumberStrategy DEFAULT_OBJECT_TO_NUMBER_STRATEGY = ToNumberPolicy.DOUBLE;
static final ToNumberStrategy DEFAULT_NUMBER_TO_NUMBER_STRATEGY = ToNumberPolicy.LAZILY_PARSED_NUMBER;
private static final String JSON_NON_EXECUTABLE_PREFIX = ")]}'\n";
/**
* This thread local guards against reentrant calls to {@link #getAdapter(TypeToken)}.
* In certain object graphs, creating an adapter for a type may recursively
* require an adapter for the same type! Without intervention, the recursive
* lookup would stack overflow. We cheat by returning a proxy type adapter,
* {@link FutureTypeAdapter}, which is wired up once the initial adapter has
* been created.
*
* <p>The map stores the type adapters for ongoing {@code getAdapter} calls,
* with the type token provided to {@code getAdapter} as key and either
* {@code FutureTypeAdapter} or a regular {@code TypeAdapter} as value.
*/
private final ThreadLocal<Map<TypeToken<?>, TypeAdapter<?>>> threadLocalAdapterResults = new ThreadLocal<>();
private final ConcurrentMap<TypeToken<?>, TypeAdapter<?>> typeTokenCache = new ConcurrentHashMap<>();
private final ConstructorConstructor constructorConstructor;
private final JsonAdapterAnnotationTypeAdapterFactory jsonAdapterFactory;
final List<TypeAdapterFactory> factories;
final Excluder excluder;
final FieldNamingStrategy fieldNamingStrategy;
final Map<Type, InstanceCreator<?>> instanceCreators;
final boolean serializeNulls;
final boolean complexMapKeySerialization;
final boolean generateNonExecutableJson;
final boolean htmlSafe;
final boolean prettyPrinting;
final boolean lenient;
final boolean serializeSpecialFloatingPointValues;
final boolean useJdkUnsafe;
final String datePattern;
final int dateStyle;
final int timeStyle;
final LongSerializationPolicy longSerializationPolicy;
final List<TypeAdapterFactory> builderFactories;
final List<TypeAdapterFactory> builderHierarchyFactories;
final ToNumberStrategy objectToNumberStrategy;
final ToNumberStrategy numberToNumberStrategy;
final List<ReflectionAccessFilter> reflectionFilters;
/**
* Constructs a Gson object with default configuration. The default configuration has the
* following settings:
* <ul>
* <li>The JSON generated by <code>toJson</code> methods is in compact representation. This
* means that all the unneeded white-space is removed. You can change this behavior with
* {@link GsonBuilder#setPrettyPrinting()}. </li>
* <li>The generated JSON omits all the fields that are null. Note that nulls in arrays are
* kept as is since an array is an ordered list. Moreover, if a field is not null, but its
* generated JSON is empty, the field is kept. You can configure Gson to serialize null values
* by setting {@link GsonBuilder#serializeNulls()}.</li>
* <li>Gson provides default serialization and deserialization for Enums, {@link Map},
* {@link java.net.URL}, {@link java.net.URI}, {@link java.util.Locale}, {@link java.util.Date},
* {@link java.math.BigDecimal}, and {@link java.math.BigInteger} classes. If you would prefer
* to change the default representation, you can do so by registering a type adapter through
* {@link GsonBuilder#registerTypeAdapter(Type, Object)}. </li>
* <li>The default Date format is same as {@link java.text.DateFormat#DEFAULT}. This format
* ignores the millisecond portion of the date during serialization. You can change
* this by invoking {@link GsonBuilder#setDateFormat(int)} or
* {@link GsonBuilder#setDateFormat(String)}. </li>
* <li>By default, Gson ignores the {@link com.google.gson.annotations.Expose} annotation.
* You can enable Gson to serialize/deserialize only those fields marked with this annotation
* through {@link GsonBuilder#excludeFieldsWithoutExposeAnnotation()}. </li>
* <li>By default, Gson ignores the {@link com.google.gson.annotations.Since} annotation. You
* can enable Gson to use this annotation through {@link GsonBuilder#setVersion(double)}.</li>
* <li>The default field naming policy for the output JSON is same as in Java. So, a Java class
* field <code>versionNumber</code> will be output as <code>"versionNumber"</code> in
* JSON. The same rules are applied for mapping incoming JSON to the Java classes. You can
* change this policy through {@link GsonBuilder#setFieldNamingPolicy(FieldNamingPolicy)}.</li>
* <li>By default, Gson excludes <code>transient</code> or <code>static</code> fields from
* consideration for serialization and deserialization. You can change this behavior through
* {@link GsonBuilder#excludeFieldsWithModifiers(int...)}.</li>
* </ul>
*/
public Gson() {
this(Excluder.DEFAULT, DEFAULT_FIELD_NAMING_STRATEGY,
Collections.<Type, InstanceCreator<?>>emptyMap(), DEFAULT_SERIALIZE_NULLS,
DEFAULT_COMPLEX_MAP_KEYS, DEFAULT_JSON_NON_EXECUTABLE, DEFAULT_ESCAPE_HTML,
DEFAULT_PRETTY_PRINT, DEFAULT_LENIENT, DEFAULT_SPECIALIZE_FLOAT_VALUES,
DEFAULT_USE_JDK_UNSAFE,
LongSerializationPolicy.DEFAULT, DEFAULT_DATE_PATTERN, DateFormat.DEFAULT, DateFormat.DEFAULT,
Collections.<TypeAdapterFactory>emptyList(), Collections.<TypeAdapterFactory>emptyList(),
Collections.<TypeAdapterFactory>emptyList(), DEFAULT_OBJECT_TO_NUMBER_STRATEGY, DEFAULT_NUMBER_TO_NUMBER_STRATEGY,
Collections.<ReflectionAccessFilter>emptyList());
}
Gson(Excluder excluder, FieldNamingStrategy fieldNamingStrategy,
Map<Type, InstanceCreator<?>> instanceCreators, boolean serializeNulls,
boolean complexMapKeySerialization, boolean generateNonExecutableGson, boolean htmlSafe,
boolean prettyPrinting, boolean lenient, boolean serializeSpecialFloatingPointValues,
boolean useJdkUnsafe,
LongSerializationPolicy longSerializationPolicy, String datePattern, int dateStyle,
int timeStyle, List<TypeAdapterFactory> builderFactories,
List<TypeAdapterFactory> builderHierarchyFactories,
List<TypeAdapterFactory> factoriesToBeAdded,
ToNumberStrategy objectToNumberStrategy, ToNumberStrategy numberToNumberStrategy,
List<ReflectionAccessFilter> reflectionFilters) {
this.excluder = excluder;
this.fieldNamingStrategy = fieldNamingStrategy;
this.instanceCreators = instanceCreators;
this.constructorConstructor = new ConstructorConstructor(instanceCreators, useJdkUnsafe, reflectionFilters);
this.serializeNulls = serializeNulls;
this.complexMapKeySerialization = complexMapKeySerialization;
this.generateNonExecutableJson = generateNonExecutableGson;
this.htmlSafe = htmlSafe;
this.prettyPrinting = prettyPrinting;
this.lenient = lenient;
this.serializeSpecialFloatingPointValues = serializeSpecialFloatingPointValues;
this.useJdkUnsafe = useJdkUnsafe;
this.longSerializationPolicy = longSerializationPolicy;
this.datePattern = datePattern;
this.dateStyle = dateStyle;
this.timeStyle = timeStyle;
this.builderFactories = builderFactories;
this.builderHierarchyFactories = builderHierarchyFactories;
this.objectToNumberStrategy = objectToNumberStrategy;
this.numberToNumberStrategy = numberToNumberStrategy;
this.reflectionFilters = reflectionFilters;
List<TypeAdapterFactory> factories = new ArrayList<>();
// built-in type adapters that cannot be overridden
factories.add(TypeAdapters.JSON_ELEMENT_FACTORY);
factories.add(ObjectTypeAdapter.getFactory(objectToNumberStrategy));
// the excluder must precede all adapters that handle user-defined types
factories.add(excluder);
// users' type adapters
factories.addAll(factoriesToBeAdded);
// type adapters for basic platform types
factories.add(TypeAdapters.STRING_FACTORY);
factories.add(TypeAdapters.INTEGER_FACTORY);
factories.add(TypeAdapters.BOOLEAN_FACTORY);
factories.add(TypeAdapters.BYTE_FACTORY);
factories.add(TypeAdapters.SHORT_FACTORY);
TypeAdapter<Number> longAdapter = longAdapter(longSerializationPolicy);
factories.add(TypeAdapters.newFactory(long.class, Long.class, longAdapter));
factories.add(TypeAdapters.newFactory(double.class, Double.class,
doubleAdapter(serializeSpecialFloatingPointValues)));
factories.add(TypeAdapters.newFactory(float.class, Float.class,
floatAdapter(serializeSpecialFloatingPointValues)));
factories.add(NumberTypeAdapter.getFactory(numberToNumberStrategy));
factories.add(TypeAdapters.ATOMIC_INTEGER_FACTORY);
factories.add(TypeAdapters.ATOMIC_BOOLEAN_FACTORY);
factories.add(TypeAdapters.newFactory(AtomicLong.class, atomicLongAdapter(longAdapter)));
factories.add(TypeAdapters.newFactory(AtomicLongArray.class, atomicLongArrayAdapter(longAdapter)));
factories.add(TypeAdapters.ATOMIC_INTEGER_ARRAY_FACTORY);
factories.add(TypeAdapters.CHARACTER_FACTORY);
factories.add(TypeAdapters.STRING_BUILDER_FACTORY);
factories.add(TypeAdapters.STRING_BUFFER_FACTORY);
factories.add(TypeAdapters.newFactory(BigDecimal.class, TypeAdapters.BIG_DECIMAL));
factories.add(TypeAdapters.newFactory(BigInteger.class, TypeAdapters.BIG_INTEGER));
// Add adapter for LazilyParsedNumber because user can obtain it from Gson and then try to serialize it again
factories.add(TypeAdapters.newFactory(LazilyParsedNumber.class, TypeAdapters.LAZILY_PARSED_NUMBER));
factories.add(TypeAdapters.URL_FACTORY);
factories.add(TypeAdapters.URI_FACTORY);
factories.add(TypeAdapters.UUID_FACTORY);
factories.add(TypeAdapters.CURRENCY_FACTORY);
factories.add(TypeAdapters.LOCALE_FACTORY);
factories.add(TypeAdapters.INET_ADDRESS_FACTORY);
factories.add(TypeAdapters.BIT_SET_FACTORY);
factories.add(DateTypeAdapter.FACTORY);
factories.add(TypeAdapters.CALENDAR_FACTORY);
if (SqlTypesSupport.SUPPORTS_SQL_TYPES) {
factories.add(SqlTypesSupport.TIME_FACTORY);
factories.add(SqlTypesSupport.DATE_FACTORY);
factories.add(SqlTypesSupport.TIMESTAMP_FACTORY);
}
factories.add(ArrayTypeAdapter.FACTORY);
factories.add(TypeAdapters.CLASS_FACTORY);
// type adapters for composite and user-defined types
factories.add(new CollectionTypeAdapterFactory(constructorConstructor));
factories.add(new MapTypeAdapterFactory(constructorConstructor, complexMapKeySerialization));
this.jsonAdapterFactory = new JsonAdapterAnnotationTypeAdapterFactory(constructorConstructor);
factories.add(jsonAdapterFactory);
factories.add(TypeAdapters.ENUM_FACTORY);
factories.add(new ReflectiveTypeAdapterFactory(
constructorConstructor, fieldNamingStrategy, excluder, jsonAdapterFactory, reflectionFilters));
this.factories = Collections.unmodifiableList(factories);
}
/**
* Returns a new GsonBuilder containing all custom factories and configuration used by the current
* instance.
*
* @return a GsonBuilder instance.
* @since 2.8.3
*/
public GsonBuilder newBuilder() {
return new GsonBuilder(this);
}
/**
* @deprecated This method by accident exposes an internal Gson class; it might be removed in a
* future version.
*/
@Deprecated
public Excluder excluder() {
return excluder;
}
/**
* Returns the field naming strategy used by this Gson instance.
*
* @see GsonBuilder#setFieldNamingStrategy(FieldNamingStrategy)
*/
public FieldNamingStrategy fieldNamingStrategy() {
return fieldNamingStrategy;
}
/**
* Returns whether this Gson instance is serializing JSON object properties with
* {@code null} values, or just omits them.
*
* @see GsonBuilder#serializeNulls()
*/
public boolean serializeNulls() {
return serializeNulls;
}
/**
* Returns whether this Gson instance produces JSON output which is
* HTML-safe, that means all HTML characters are escaped.
*
* @see GsonBuilder#disableHtmlEscaping()
*/
public boolean htmlSafe() {
return htmlSafe;
}
private TypeAdapter<Number> doubleAdapter(boolean serializeSpecialFloatingPointValues) {
if (serializeSpecialFloatingPointValues) {
return TypeAdapters.DOUBLE;
}
return new TypeAdapter<Number>() {
@Override public Double read(JsonReader in) throws IOException {
if (in.peek() == JsonToken.NULL) {
in.nextNull();
return null;
}
return in.nextDouble();
}
@Override public void write(JsonWriter out, Number value) throws IOException {
if (value == null) {
out.nullValue();
return;
}
double doubleValue = value.doubleValue();
checkValidFloatingPoint(doubleValue);
out.value(doubleValue);
}
};
}
private TypeAdapter<Number> floatAdapter(boolean serializeSpecialFloatingPointValues) {
if (serializeSpecialFloatingPointValues) {
return TypeAdapters.FLOAT;
}
return new TypeAdapter<Number>() {
@Override public Float read(JsonReader in) throws IOException {
if (in.peek() == JsonToken.NULL) {
in.nextNull();
return null;
}
return (float) in.nextDouble();
}
@Override public void write(JsonWriter out, Number value) throws IOException {
if (value == null) {
out.nullValue();
return;
}
float floatValue = value.floatValue();
checkValidFloatingPoint(floatValue);
// For backward compatibility don't call `JsonWriter.value(float)` because that method has
// been newly added and not all custom JsonWriter implementations might override it yet
Number floatNumber = value instanceof Float ? value : floatValue;
out.value(floatNumber);
}
};
}
static void checkValidFloatingPoint(double value) {
if (Double.isNaN(value) || Double.isInfinite(value)) {
throw new IllegalArgumentException(value
+ " is not a valid double value as per JSON specification. To override this"
+ " behavior, use GsonBuilder.serializeSpecialFloatingPointValues() method.");
}
}
private static TypeAdapter<Number> longAdapter(LongSerializationPolicy longSerializationPolicy) {
if (longSerializationPolicy == LongSerializationPolicy.DEFAULT) {
return TypeAdapters.LONG;
}
return new TypeAdapter<Number>() {
@Override public Number read(JsonReader in) throws IOException {
if (in.peek() == JsonToken.NULL) {
in.nextNull();
return null;
}
return in.nextLong();
}
@Override public void write(JsonWriter out, Number value) throws IOException {
if (value == null) {
out.nullValue();
return;
}
out.value(value.toString());
}
};
}
private static TypeAdapter<AtomicLong> atomicLongAdapter(final TypeAdapter<Number> longAdapter) {
return new TypeAdapter<AtomicLong>() {
@Override public void write(JsonWriter out, AtomicLong value) throws IOException {
longAdapter.write(out, value.get());
}
@Override public AtomicLong read(JsonReader in) throws IOException {
Number value = longAdapter.read(in);
return new AtomicLong(value.longValue());
}
}.nullSafe();
}
private static TypeAdapter<AtomicLongArray> atomicLongArrayAdapter(final TypeAdapter<Number> longAdapter) {
return new TypeAdapter<AtomicLongArray>() {
@Override public void write(JsonWriter out, AtomicLongArray value) throws IOException {
out.beginArray();
for (int i = 0, length = value.length(); i < length; i++) {
longAdapter.write(out, value.get(i));
}
out.endArray();
}
@Override public AtomicLongArray read(JsonReader in) throws IOException {
List<Long> list = new ArrayList<>();
in.beginArray();
while (in.hasNext()) {
long value = longAdapter.read(in).longValue();
list.add(value);
}
in.endArray();
int length = list.size();
AtomicLongArray array = new AtomicLongArray(length);
for (int i = 0; i < length; ++i) {
array.set(i, list.get(i));
}
return array;
}
}.nullSafe();
}
/**
* Returns the type adapter for {@code type}.
*
* <p>When calling this method concurrently from multiple threads and requesting
* an adapter for the same type this method may return different {@code TypeAdapter}
* instances. However, that should normally not be an issue because {@code TypeAdapter}
* implementations are supposed to be stateless.
*
* @throws IllegalArgumentException if this Gson instance cannot serialize and
* deserialize {@code type}.
*/
public <T> TypeAdapter<T> getAdapter(TypeToken<T> type) {
Objects.requireNonNull(type, "type must not be null");
TypeAdapter<?> cached = typeTokenCache.get(type);
if (cached != null) {
@SuppressWarnings("unchecked")
TypeAdapter<T> adapter = (TypeAdapter<T>) cached;
return adapter;
}
Map<TypeToken<?>, TypeAdapter<?>> threadCalls = threadLocalAdapterResults.get();
boolean isInitialAdapterRequest = false;
if (threadCalls == null) {
threadCalls = new HashMap<>();
threadLocalAdapterResults.set(threadCalls);
isInitialAdapterRequest = true;
} else {
// the key and value type parameters always agree
@SuppressWarnings("unchecked")
TypeAdapter<T> ongoingCall = (TypeAdapter<T>) threadCalls.get(type);
if (ongoingCall != null) {
return ongoingCall;
}
}
TypeAdapter<T> candidate = null;
try {
FutureTypeAdapter<T> call = new FutureTypeAdapter<>();
threadCalls.put(type, call);
for (TypeAdapterFactory factory : factories) {
candidate = factory.create(this, type);
if (candidate != null) {
call.setDelegate(candidate);
// Replace future adapter with actual adapter
threadCalls.put(type, candidate);
break;
}
}
} finally {
if (isInitialAdapterRequest) {
threadLocalAdapterResults.remove();
}
}
if (candidate == null) {
throw new IllegalArgumentException("GSON (" + GsonBuildConfig.VERSION + ") cannot handle " + type);
}
if (isInitialAdapterRequest) {
/*
* Publish resolved adapters to all threads
* Can only do this for the initial request because cyclic dependency TypeA -> TypeB -> TypeA
* would otherwise publish adapter for TypeB which uses not yet resolved adapter for TypeA
* See https://github.com/google/gson/issues/625
*/
typeTokenCache.putAll(threadCalls);
}
return candidate;
}
/**
* This method is used to get an alternate type adapter for the specified type. This is used
* to access a type adapter that is overridden by a {@link TypeAdapterFactory} that you
* may have registered. This features is typically used when you want to register a type
* adapter that does a little bit of work but then delegates further processing to the Gson
* default type adapter. Here is an example:
* <p>Let's say we want to write a type adapter that counts the number of objects being read
* from or written to JSON. We can achieve this by writing a type adapter factory that uses
* the <code>getDelegateAdapter</code> method:
* <pre> {@code
* class StatsTypeAdapterFactory implements TypeAdapterFactory {
* public int numReads = 0;
* public int numWrites = 0;
* public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
* final TypeAdapter<T> delegate = gson.getDelegateAdapter(this, type);
* return new TypeAdapter<T>() {
* public void write(JsonWriter out, T value) throws IOException {
* ++numWrites;
* delegate.write(out, value);
* }
* public T read(JsonReader in) throws IOException {
* ++numReads;
* return delegate.read(in);
* }
* };
* }
* }
* } </pre>
* This factory can now be used like this:
* <pre> {@code
* StatsTypeAdapterFactory stats = new StatsTypeAdapterFactory();
* Gson gson = new GsonBuilder().registerTypeAdapterFactory(stats).create();
* // Call gson.toJson() and fromJson methods on objects
* System.out.println("Num JSON reads" + stats.numReads);
* System.out.println("Num JSON writes" + stats.numWrites);
* }</pre>
* Note that this call will skip all factories registered before {@code skipPast}. In case of
* multiple TypeAdapterFactories registered it is up to the caller of this function to insure
* that the order of registration does not prevent this method from reaching a factory they
* would expect to reply from this call.
* Note that since you can not override type adapter factories for String and Java primitive
* types, our stats factory will not count the number of String or primitives that will be
* read or written.
* @param skipPast The type adapter factory that needs to be skipped while searching for
* a matching type adapter. In most cases, you should just pass <i>this</i> (the type adapter
* factory from where {@code getDelegateAdapter} method is being invoked).
* @param type Type for which the delegate adapter is being searched for.
*
* @since 2.2
*/
public <T> TypeAdapter<T> getDelegateAdapter(TypeAdapterFactory skipPast, TypeToken<T> type) {
// Hack. If the skipPast factory isn't registered, assume the factory is being requested via
// our @JsonAdapter annotation.
if (!factories.contains(skipPast)) {
skipPast = jsonAdapterFactory;
}
boolean skipPastFound = false;
for (TypeAdapterFactory factory : factories) {
if (!skipPastFound) {
if (factory == skipPast) {
skipPastFound = true;
}
continue;
}
TypeAdapter<T> candidate = factory.create(this, type);
if (candidate != null) {
return candidate;
}
}
throw new IllegalArgumentException("GSON cannot serialize " + type);
}
/**
* Returns the type adapter for {@code type}.
*
* @throws IllegalArgumentException if this Gson instance cannot serialize and
* deserialize {@code type}.
*/
public <T> TypeAdapter<T> getAdapter(Class<T> type) {
return getAdapter(TypeToken.get(type));
}
/**
* This method serializes the specified object into its equivalent representation as a tree of
* {@link JsonElement}s. This method should be used when the specified object is not a generic
* type. This method uses {@link Class#getClass()} to get the type for the specified object, but
* the {@code getClass()} loses the generic type information because of the Type Erasure feature
* of Java. Note that this method works fine if any of the object fields are of generic type,
* just the object itself should not be of a generic type. If the object is of generic type, use
* {@link #toJsonTree(Object, Type)} instead.
*
* @param src the object for which JSON representation is to be created
* @return JSON representation of {@code src}.
* @since 1.4
*
* @see #toJsonTree(Object, Type)
*/
public JsonElement toJsonTree(Object src) {
if (src == null) {
return JsonNull.INSTANCE;
}
return toJsonTree(src, src.getClass());
}
/**
* This method serializes the specified object, including those of generic types, into its
* equivalent representation as a tree of {@link JsonElement}s. This method must be used if the
* specified object is a generic type. For non-generic objects, use {@link #toJsonTree(Object)}
* instead.
*
* @param src the object for which JSON representation is to be created
* @param typeOfSrc The specific genericized type of src. You can obtain
* this type by using the {@link com.google.gson.reflect.TypeToken} class. For example,
* to get the type for {@code Collection<Foo>}, you should use:
* <pre>
* Type typeOfSrc = new TypeToken<Collection<Foo>>(){}.getType();
* </pre>
* @return Json representation of {@code src}
* @since 1.4
*
* @see #toJsonTree(Object)
*/
public JsonElement toJsonTree(Object src, Type typeOfSrc) {
JsonTreeWriter writer = new JsonTreeWriter();
toJson(src, typeOfSrc, writer);
return writer.get();
}
/**
* This method serializes the specified object into its equivalent JSON representation.
* This method should be used when the specified object is not a generic type. This method uses
* {@link Class#getClass()} to get the type for the specified object, but the
* {@code getClass()} loses the generic type information because of the Type Erasure feature
* of Java. Note that this method works fine if any of the object fields are of generic type,
* just the object itself should not be of a generic type. If the object is of generic type, use
* {@link #toJson(Object, Type)} instead. If you want to write out the object to a
* {@link Writer}, use {@link #toJson(Object, Appendable)} instead.
*
* @param src the object for which JSON representation is to be created
* @return Json representation of {@code src}.
*
* @see #toJson(Object, Appendable)
* @see #toJson(Object, Type)
*/
public String toJson(Object src) {
if (src == null) {
return toJson(JsonNull.INSTANCE);
}
return toJson(src, src.getClass());
}
/**
* This method serializes the specified object, including those of generic types, into its
* equivalent JSON representation. This method must be used if the specified object is a generic
* type. For non-generic objects, use {@link #toJson(Object)} instead. If you want to write out
* the object to a {@link Appendable}, use {@link #toJson(Object, Type, Appendable)} instead.
*
* @param src the object for which JSON representation is to be created
* @param typeOfSrc The specific genericized type of src. You can obtain
* this type by using the {@link com.google.gson.reflect.TypeToken} class. For example,
* to get the type for {@code Collection<Foo>}, you should use:
* <pre>
* Type typeOfSrc = new TypeToken<Collection<Foo>>(){}.getType();
* </pre>
* @return JSON representation of {@code src}
*
* @see #toJson(Object, Type, Appendable)
* @see #toJson(Object)
*/
public String toJson(Object src, Type typeOfSrc) {
StringWriter writer = new StringWriter();
toJson(src, typeOfSrc, writer);
return writer.toString();
}
/**
* This method serializes the specified object into its equivalent JSON representation and
* writes it to the writer.
* This method should be used when the specified object is not a generic type. This method uses
* {@link Class#getClass()} to get the type for the specified object, but the
* {@code getClass()} loses the generic type information because of the Type Erasure feature
* of Java. Note that this method works fine if any of the object fields are of generic type,
* just the object itself should not be of a generic type. If the object is of generic type, use
* {@link #toJson(Object, Type, Appendable)} instead.
*
* @param src the object for which JSON representation is to be created
* @param writer Writer to which the JSON representation needs to be written
* @throws JsonIOException if there was a problem writing to the writer
* @since 1.2
*
* @see #toJson(Object)
* @see #toJson(Object, Type, Appendable)
*/
public void toJson(Object src, Appendable writer) throws JsonIOException {
if (src != null) {
toJson(src, src.getClass(), writer);
} else {
toJson(JsonNull.INSTANCE, writer);
}
}
/**
* This method serializes the specified object, including those of generic types, into its
* equivalent JSON representation and writes it to the writer.
* This method must be used if the specified object is a generic type. For non-generic objects,
* use {@link #toJson(Object, Appendable)} instead.
*
* @param src the object for which JSON representation is to be created
* @param typeOfSrc The specific genericized type of src. You can obtain
* this type by using the {@link com.google.gson.reflect.TypeToken} class. For example,
* to get the type for {@code Collection<Foo>}, you should use:
* <pre>
* Type typeOfSrc = new TypeToken<Collection<Foo>>(){}.getType();
* </pre>
* @param writer Writer to which the JSON representation of src needs to be written.
* @throws JsonIOException if there was a problem writing to the writer
* @since 1.2
*
* @see #toJson(Object, Type)
* @see #toJson(Object, Appendable)
*/
public void toJson(Object src, Type typeOfSrc, Appendable writer) throws JsonIOException {
try {
JsonWriter jsonWriter = newJsonWriter(Streams.writerForAppendable(writer));
toJson(src, typeOfSrc, jsonWriter);
} catch (IOException e) {
throw new JsonIOException(e);
}
}
/**
* Writes the JSON representation of {@code src} of type {@code typeOfSrc} to
* {@code writer}.
*
* <p>The JSON data is written in {@linkplain JsonWriter#setLenient(boolean) lenient mode},
* regardless of the lenient mode setting of the provided writer. The lenient mode setting
* of the writer is restored once this method returns.
*
* <p>The 'HTML-safe' and 'serialize {@code null}' settings of this {@code Gson} instance
* (configured by the {@link GsonBuilder}) are applied, and the original settings of the
* writer are restored once this method returns.
*
* @throws JsonIOException if there was a problem writing to the writer
*/
public void toJson(Object src, Type typeOfSrc, JsonWriter writer) throws JsonIOException {
@SuppressWarnings("unchecked")
TypeAdapter<Object> adapter = (TypeAdapter<Object>) getAdapter(TypeToken.get(typeOfSrc));
boolean oldLenient = writer.isLenient();
writer.setLenient(true);
boolean oldHtmlSafe = writer.isHtmlSafe();
writer.setHtmlSafe(htmlSafe);
boolean oldSerializeNulls = writer.getSerializeNulls();
writer.setSerializeNulls(serializeNulls);
try {
adapter.write(writer, src);
} catch (IOException e) {
throw new JsonIOException(e);
} catch (AssertionError e) {
throw new AssertionError("AssertionError (GSON " + GsonBuildConfig.VERSION + "): " + e.getMessage(), e);
} finally {
writer.setLenient(oldLenient);
writer.setHtmlSafe(oldHtmlSafe);
writer.setSerializeNulls(oldSerializeNulls);
}
}
/**
* Converts a tree of {@link JsonElement}s into its equivalent JSON representation.
*
* @param jsonElement root of a tree of {@link JsonElement}s
* @return JSON String representation of the tree
* @since 1.4
*/
public String toJson(JsonElement jsonElement) {
StringWriter writer = new StringWriter();
toJson(jsonElement, writer);
return writer.toString();
}
/**
* Writes out the equivalent JSON for a tree of {@link JsonElement}s.
*
* @param jsonElement root of a tree of {@link JsonElement}s
* @param writer Writer to which the JSON representation needs to be written
* @throws JsonIOException if there was a problem writing to the writer
* @since 1.4
*/
public void toJson(JsonElement jsonElement, Appendable writer) throws JsonIOException {
try {
JsonWriter jsonWriter = newJsonWriter(Streams.writerForAppendable(writer));
toJson(jsonElement, jsonWriter);
} catch (IOException e) {
throw new JsonIOException(e);
}
}
/**
* Returns a new JSON writer configured for the settings on this Gson instance.
*
* <p>The following settings are considered:
* <ul>
* <li>{@link GsonBuilder#disableHtmlEscaping()}</li>
* <li>{@link GsonBuilder#generateNonExecutableJson()}</li>
* <li>{@link GsonBuilder#serializeNulls()}</li>
* <li>{@link GsonBuilder#setLenient()}</li>
* <li>{@link GsonBuilder#setPrettyPrinting()}</li>
* </ul>
*/
public JsonWriter newJsonWriter(Writer writer) throws IOException {
if (generateNonExecutableJson) {
writer.write(JSON_NON_EXECUTABLE_PREFIX);
}
JsonWriter jsonWriter = new JsonWriter(writer);
if (prettyPrinting) {
jsonWriter.setIndent(" ");
}
jsonWriter.setHtmlSafe(htmlSafe);
jsonWriter.setLenient(lenient);
jsonWriter.setSerializeNulls(serializeNulls);
return jsonWriter;
}
/**
* Returns a new JSON reader configured for the settings on this Gson instance.
*
* <p>The following settings are considered:
* <ul>
* <li>{@link GsonBuilder#setLenient()}</li>
* </ul>
*/
public JsonReader newJsonReader(Reader reader) {
JsonReader jsonReader = new JsonReader(reader);
jsonReader.setLenient(lenient);
return jsonReader;
}
/**
* Writes the JSON for {@code jsonElement} to {@code writer}.
*
* <p>The JSON data is written in {@linkplain JsonWriter#setLenient(boolean) lenient mode},
* regardless of the lenient mode setting of the provided writer. The lenient mode setting
* of the writer is restored once this method returns.
*
* <p>The 'HTML-safe' and 'serialize {@code null}' settings of this {@code Gson} instance
* (configured by the {@link GsonBuilder}) are applied, and the original settings of the
* writer are restored once this method returns.
*
* @throws JsonIOException if there was a problem writing to the writer
*/
public void toJson(JsonElement jsonElement, JsonWriter writer) throws JsonIOException {
boolean oldLenient = writer.isLenient();
writer.setLenient(true);
boolean oldHtmlSafe = writer.isHtmlSafe();
writer.setHtmlSafe(htmlSafe);
boolean oldSerializeNulls = writer.getSerializeNulls();
writer.setSerializeNulls(serializeNulls);
try {
Streams.write(jsonElement, writer);
} catch (IOException e) {
throw new JsonIOException(e);
} catch (AssertionError e) {
throw new AssertionError("AssertionError (GSON " + GsonBuildConfig.VERSION + "): " + e.getMessage(), e);
} finally {
writer.setLenient(oldLenient);
writer.setHtmlSafe(oldHtmlSafe);
writer.setSerializeNulls(oldSerializeNulls);
}
}
/**
* This method deserializes the specified JSON into an object of the specified class. It is not
* suitable to use if the specified class is a generic type since it will not have the generic
* type information because of the Type Erasure feature of Java. Therefore, this method should not
* be used if the desired type is a generic type. Note that this method works fine if the any of
* the fields of the specified object are generics, just the object itself should not be a
* generic type. For the cases when the object is of generic type, invoke
* {@link #fromJson(String, TypeToken)}. If you have the JSON in a {@link Reader} instead of
* a String, use {@link #fromJson(Reader, Class)} instead.
*
* <p>An exception is thrown if the JSON string has multiple top-level JSON elements, or if there
* is trailing data. Use {@link #fromJson(JsonReader, Type)} if this behavior is not desired.
*
* @param <T> the type of the desired object
* @param json the string from which the object is to be deserialized
* @param classOfT the class of T
* @return an object of type T from the string. Returns {@code null} if {@code json} is {@code null}
* or if {@code json} is empty.
* @throws JsonSyntaxException if json is not a valid representation for an object of type
* classOfT
*
* @see #fromJson(Reader, Class)
* @see #fromJson(String, TypeToken)
*/
public <T> T fromJson(String json, Class<T> classOfT) throws JsonSyntaxException {
T object = fromJson(json, TypeToken.get(classOfT));
return Primitives.wrap(classOfT).cast(object);
}
/**
* This method deserializes the specified JSON into an object of the specified type. This method
* is useful if the specified object is a generic type. For non-generic objects, use
* {@link #fromJson(String, Class)} instead. If you have the JSON in a {@link Reader} instead of
* a String, use {@link #fromJson(Reader, Type)} instead.
*
* <p>Since {@code Type} is not parameterized by T, this method is not type-safe and
* should be used carefully. If you are creating the {@code Type} from a {@link TypeToken},
* prefer using {@link #fromJson(String, TypeToken)} instead since its return type is based
* on the {@code TypeToken} and is therefore more type-safe.
*
* <p>An exception is thrown if the JSON string has multiple top-level JSON elements,
* or if there is trailing data. Use {@link #fromJson(JsonReader, Type)} if this behavior is
* not desired.
*