Use this builder to construct a {@link Gson} instance when you need to set configuration - * options other than the default. For {@link Gson} with default configuration, it is simpler to - * use {@code new Gson()}. {@code GsonBuilder} is best used by creating it, and then invoking its - * various configuration methods, and finally calling create.
- * - *The following is an example shows how to use the {@code GsonBuilder} to construct a Gson - * instance: - * - *
- * Gson gson = new GsonBuilder() - * .registerTypeAdapter(Id.class, new IdTypeAdapter()) - * .enableComplexMapKeySerialization() - * .serializeNulls() - * .setDateFormat(DateFormat.LONG) - * .setFieldNamingPolicy(FieldNamingPolicy.UPPER_CAMEL_CASE) - * .setPrettyPrinting() - * .setVersion(1.0) - * .create(); - *- * - *
NOTES: - *
Below is an example: - *
{@code
- * Gson gson = new GsonBuilder()
- * .register(Point.class, new MyPointTypeAdapter())
- * .enableComplexMapKeySerialization()
- * .create();
- *
- * Map original = new LinkedHashMap();
- * original.put(new Point(5, 6), "a");
- * original.put(new Point(8, 8), "b");
- * System.out.println(gson.toJson(original, type));
- * }
- * The above code prints this JSON object: {@code
- * {
- * "(5,6)": "a",
- * "(8,8)": "b"
- * }
- * }
- *
- * Given the assumption above, a {@code Map Below is an example of serializing complex types as JSON arrays:
- * The date format will be used to serialize and deserialize {@link java.util.Date}, {@link
- * java.sql.Timestamp} and {@link java.sql.Date}.
- *
- * Note that this pattern must abide by the convention provided by {@code SimpleDateFormat}
- * class. See the documentation in {@link java.text.SimpleDateFormat} for more information on
- * valid date and time patterns. Note that this style value should be one of the predefined constants in the
- * {@code DateFormat} class. See the documentation in {@link java.text.DateFormat} for more
- * information on the valid style constants. Note that this style value should be one of the predefined constants in the
- * {@code DateFormat} class. See the documentation in {@link java.text.DateFormat} for more
- * information on the valid style constants. This registers the type specified and no other types: you must manually register related
- * types! For example, applications registering {@code boolean.class} should also register {@code
- * Boolean.class}.
- *
- * @param type the type definition for the type adapter being registered
- * @param typeAdapter This object must implement at least one of the {@link TypeAdapter},
- * {@link InstanceCreator}, {@link JsonSerializer}, and a {@link JsonDeserializer} interfaces.
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- */
- @SuppressWarnings({"unchecked", "rawtypes"})
- public GsonBuilder registerTypeAdapter(Type type, Object typeAdapter) {
- $Gson$Preconditions.checkArgument(typeAdapter instanceof JsonSerializer
- || typeAdapter instanceof JsonDeserializer
- || typeAdapter instanceof InstanceCreator
- || typeAdapter instanceof TypeAdapter);
- if (typeAdapter instanceof InstanceCreator) {
- instanceCreators.put(type, (InstanceCreator) typeAdapter);
- }
- if (typeAdapter instanceof JsonSerializer || typeAdapter instanceof JsonDeserializer) {
- TypeToken typeToken = TypeToken.get(type);
- factories.add(TreeTypeAdapter.newFactoryWithMatchRawType(typeToken, typeAdapter));
- }
- if (typeAdapter instanceof TypeAdapter) {
- factories.add(TypeAdapters.newFactory(TypeToken.get(type), (TypeAdapter)typeAdapter));
- }
- return this;
- }
-
- /**
- * Register a factory for type adapters. Registering a factory is useful when the type
- * adapter needs to be configured based on the type of the field being processed. Gson
- * is designed to handle a large number of factories, so you should consider registering
- * them to be at par with registering an individual type adapter.
- *
- * @since 2.1
- */
- public GsonBuilder registerTypeAdapterFactory(TypeAdapterFactory factory) {
- factories.add(factory);
- return this;
- }
-
- /**
- * Configures Gson for custom serialization or deserialization for an inheritance type hierarchy.
- * This method combines the registration of a {@link TypeAdapter}, {@link JsonSerializer} and
- * a {@link JsonDeserializer}. If a type adapter was previously registered for the specified
- * type hierarchy, it is overridden. If a type adapter is registered for a specific type in
- * the type hierarchy, it will be invoked instead of the one registered for the type hierarchy.
- *
- * @param baseType the class definition for the type adapter being registered for the base class
- * or interface
- * @param typeAdapter This object must implement at least one of {@link TypeAdapter},
- * {@link JsonSerializer} or {@link JsonDeserializer} interfaces.
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.7
- */
- @SuppressWarnings({"unchecked", "rawtypes"})
- public GsonBuilder registerTypeHierarchyAdapter(Class baseType, Object typeAdapter) {
- $Gson$Preconditions.checkArgument(typeAdapter instanceof JsonSerializer
- || typeAdapter instanceof JsonDeserializer
- || typeAdapter instanceof TypeAdapter);
- if (typeAdapter instanceof JsonDeserializer || typeAdapter instanceof JsonSerializer) {
- hierarchyFactories.add(0,
- TreeTypeAdapter.newTypeHierarchyFactory(baseType, typeAdapter));
- }
- if (typeAdapter instanceof TypeAdapter) {
- factories.add(TypeAdapters.newTypeHierarchyFactory(baseType, (TypeAdapter)typeAdapter));
- }
- return this;
- }
-
- /**
- * Section 2.4 of JSON specification disallows
- * special double values (NaN, Infinity, -Infinity). However,
- * Javascript
- * specification (see section 4.3.20, 4.3.22, 4.3.23) allows these values as valid Javascript
- * values. Moreover, most JavaScript engines will accept these special values in JSON without
- * problem. So, at a practical level, it makes sense to accept these values as valid JSON even
- * though JSON specification disallows them.
- *
- * Gson always accepts these special values during deserialization. However, it outputs
- * strictly compliant JSON. Hence, if it encounters a float value {@link Float#NaN},
- * {@link Float#POSITIVE_INFINITY}, {@link Float#NEGATIVE_INFINITY}, or a double value
- * {@link Double#NaN}, {@link Double#POSITIVE_INFINITY}, {@link Double#NEGATIVE_INFINITY}, it
- * will throw an {@link IllegalArgumentException}. This method provides a way to override the
- * default behavior when you know that the JSON receiver will be able to handle these special
- * values.
- *
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.3
- */
- public GsonBuilder serializeSpecialFloatingPointValues() {
- this.serializeSpecialFloatingPointValues = true;
- return this;
- }
-
- /**
- * Creates a {@link Gson} instance based on the current configuration. This method is free of
- * side-effects to this {@code GsonBuilder} instance and hence can be called multiple times.
- *
- * @return an instance of Gson configured with the options currently set in this builder
- */
- public Gson create() {
- List {@code
- * Gson gson = new GsonBuilder()
- * .enableComplexMapKeySerialization()
- * .create();
- *
- * Map {@code
- * [
- * [
- * {
- * "x": 5,
- * "y": 6
- * },
- * "a"
- * ],
- * [
- * {
- * "x": 8,
- * "y": 8
- * },
- * "b"
- * ]
- * ]
- * }
- *
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.7
- */
- public GsonBuilder enableComplexMapKeySerialization() {
- complexMapKeySerialization = true;
- return this;
- }
-
- /**
- * Configures Gson to exclude inner classes during serialization.
- *
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.3
- */
- public GsonBuilder disableInnerClassSerialization() {
- excluder = excluder.disableInnerClassSerialization();
- return this;
- }
-
- /**
- * Configures Gson to apply a specific serialization policy for {@code Long} and {@code long}
- * objects.
- *
- * @param serializationPolicy the particular policy to use for serializing longs.
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.3
- */
- public GsonBuilder setLongSerializationPolicy(LongSerializationPolicy serializationPolicy) {
- this.longSerializationPolicy = serializationPolicy;
- return this;
- }
-
- /**
- * Configures Gson to apply a specific naming policy to an object's field during serialization
- * and deserialization.
- *
- * @param namingConvention the JSON field naming convention to use for serialization and
- * deserialization.
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- */
- public GsonBuilder setFieldNamingPolicy(FieldNamingPolicy namingConvention) {
- this.fieldNamingPolicy = namingConvention;
- return this;
- }
-
- /**
- * Configures Gson to apply a specific naming policy strategy to an object's field during
- * serialization and deserialization.
- *
- * @param fieldNamingStrategy the actual naming strategy to apply to the fields
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.3
- */
- public GsonBuilder setFieldNamingStrategy(FieldNamingStrategy fieldNamingStrategy) {
- this.fieldNamingPolicy = fieldNamingStrategy;
- return this;
- }
-
- /**
- * Configures Gson to apply a set of exclusion strategies during both serialization and
- * deserialization. Each of the {@code strategies} will be applied as a disjunction rule.
- * This means that if one of the {@code strategies} suggests that a field (or class) should be
- * skipped then that field (or object) is skipped during serializaiton/deserialization.
- *
- * @param strategies the set of strategy object to apply during object (de)serialization.
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.4
- */
- public GsonBuilder setExclusionStrategies(ExclusionStrategy... strategies) {
- for (ExclusionStrategy strategy : strategies) {
- excluder = excluder.withExclusionStrategy(strategy, true, true);
- }
- return this;
- }
-
- /**
- * Configures Gson to apply the passed in exclusion strategy during serialization.
- * If this method is invoked numerous times with different exclusion strategy objects
- * then the exclusion strategies that were added will be applied as a disjunction rule.
- * This means that if one of the added exclusion strategies suggests that a field (or
- * class) should be skipped then that field (or object) is skipped during its
- * serialization.
- *
- * @param strategy an exclusion strategy to apply during serialization.
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.7
- */
- public GsonBuilder addSerializationExclusionStrategy(ExclusionStrategy strategy) {
- excluder = excluder.withExclusionStrategy(strategy, true, false);
- return this;
- }
-
- /**
- * Configures Gson to apply the passed in exclusion strategy during deserialization.
- * If this method is invoked numerous times with different exclusion strategy objects
- * then the exclusion strategies that were added will be applied as a disjunction rule.
- * This means that if one of the added exclusion strategies suggests that a field (or
- * class) should be skipped then that field (or object) is skipped during its
- * deserialization.
- *
- * @param strategy an exclusion strategy to apply during deserialization.
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.7
- */
- public GsonBuilder addDeserializationExclusionStrategy(ExclusionStrategy strategy) {
- excluder = excluder.withExclusionStrategy(strategy, false, true);
- return this;
- }
-
- /**
- * Configures Gson to output Json that fits in a page for pretty printing. This option only
- * affects Json serialization.
- *
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- */
- public GsonBuilder setPrettyPrinting() {
- prettyPrinting = true;
- return this;
- }
-
- /**
- * By default, Gson escapes HTML characters such as < > etc. Use this option to configure
- * Gson to pass-through HTML characters as is.
- *
- * @return a reference to this {@code GsonBuilder} object to fulfill the "Builder" pattern
- * @since 1.3
- */
- public GsonBuilder disableHtmlEscaping() {
- this.escapeHtmlChars = false;
- return this;
- }
-
- /**
- * Configures Gson to serialize {@code Date} objects according to the pattern provided. You can
- * call this method or {@link #setDateFormat(int)} multiple times, but only the last invocation
- * will be used to decide the serialization format.
- *
- *