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package com.fasterxml.jackson.databind;

import com.fasterxml.jackson.databind.cfg.ConfigFeature;
import com.fasterxml.jackson.databind.exc.InvalidNullException;

/**
 * Enumeration that defines simple on/off features that affect
 * the way Java objects are deserialized from JSON
 *

* Note that features can be set both through * {@link ObjectMapper} (as sort of defaults) and through * {@link ObjectReader}. * In first case these defaults must follow "config-then-use" patterns * (i.e. defined once, not changed afterwards); all per-call * changes must be done using {@link ObjectReader}. *

* Note that features that do not indicate version of inclusion * were available in Jackson 2.0 (or earlier); only later additions * indicate version of inclusion. */ public enum DeserializationFeature implements ConfigFeature { /* /****************************************************** /* Value (mostly scalar) conversion features /****************************************************** */ /** * Feature that determines whether JSON floating point numbers * are to be deserialized into {@link java.math.BigDecimal}s * if only generic type description (either {@link Object} or * {@link Number}, or within untyped {@link java.util.Map} * or {@link java.util.Collection} context) is available. * If enabled such values will be deserialized as {@link java.math.BigDecimal}s; * if disabled, will be deserialized as {@link Double}s. *

* NOTE: one aspect of {@link java.math.BigDecimal} handling that may need * configuring is whether trailing zeroes are trimmed: * {@link com.fasterxml.jackson.databind.node.JsonNodeFactory} has * {@link com.fasterxml.jackson.databind.node.JsonNodeFactory#withExactBigDecimals} for * changing default behavior (default is for trailing zeroes to be trimmed). *

* Feature is disabled by default, meaning that "untyped" floating * point numbers will by default be deserialized as {@link Double}s * (choice is for performance reason -- BigDecimals are slower than * Doubles). */ USE_BIG_DECIMAL_FOR_FLOATS(false), /** * Feature that determines whether JSON integral (non-floating-point) * numbers are to be deserialized into {@link java.math.BigInteger}s * if only generic type description (either {@link Object} or * {@link Number}, or within untyped {@link java.util.Map} * or {@link java.util.Collection} context) is available. * If enabled such values will be deserialized as * {@link java.math.BigInteger}s; * if disabled, will be deserialized as "smallest" available type, * which is either {@link Integer}, {@link Long} or * {@link java.math.BigInteger}, depending on number of digits. *

* Feature is disabled by default, meaning that "untyped" integral * numbers will by default be deserialized using whatever * is the most compact integral type, to optimize efficiency. */ USE_BIG_INTEGER_FOR_INTS(false), /** * Feature that determines how "small" JSON integral (non-floating-point) * numbers -- ones that fit in 32-bit signed integer (`int`) -- are bound * when target type is loosely typed as {@link Object} or {@link Number} * (or within untyped {@link java.util.Map} or {@link java.util.Collection} context). * If enabled, such values will be deserialized as {@link java.lang.Long}; * if disabled, they will be deserialized as "smallest" available type, * {@link Integer}. *

* Note: if {@link #USE_BIG_INTEGER_FOR_INTS} is enabled, it has precedence * over this setting, forcing use of {@link java.math.BigInteger} for all * integral values. *

* Feature is disabled by default, meaning that "untyped" integral * numbers will by default be deserialized using {@link java.lang.Integer} * if value fits. * * @since 2.6 */ USE_LONG_FOR_INTS(false), /** * Feature that determines whether JSON Array is mapped to * Object[] or {@code List} when binding * "untyped" objects (ones with nominal type of java.lang.Object). * If true, binds as Object[]; if false, as {@code List}. *

* Feature is disabled by default, meaning that JSON arrays are bound as * {@link java.util.List}s. */ USE_JAVA_ARRAY_FOR_JSON_ARRAY(false), /* /****************************************************** /* Error handling features /****************************************************** */ /** * Feature that determines whether encountering of unknown * properties (ones that do not map to a property, and there is * no "any setter" or handler that can handle it) * should result in a failure (by throwing a * {@link JsonMappingException}) or not. * This setting only takes effect after all other handling * methods for unknown properties have been tried, and * property remains unhandled. *

* Feature is enabled by default (meaning that a * {@link JsonMappingException} will be thrown if an unknown property * is encountered). */ FAIL_ON_UNKNOWN_PROPERTIES(true), /** * Feature that determines whether encountering of JSON null * is an error when deserializing into Java primitive types * (like 'int' or 'double'). If it is, a {@link InvalidNullException} * is thrown to indicate this; if not, default value is used * (0 for 'int', 0.0 for double, same defaulting as what JVM uses). *

* Feature is disabled by default. */ FAIL_ON_NULL_FOR_PRIMITIVES(false), /** * Feature that determines whether JSON integer numbers are valid * values to be used for deserializing Java enum values. * If set to 'false' numbers are acceptable and are used to map to * ordinal() of matching enumeration value; if 'true', numbers are * not allowed and a {@link JsonMappingException} will be thrown. * Latter behavior makes sense if there is concern that accidental * mapping from integer values to enums might happen (and when enums * are always serialized as JSON Strings) *

* Feature is disabled by default. */ FAIL_ON_NUMBERS_FOR_ENUMS(false), /** * Feature that determines what happens when type of a polymorphic * value (indicated for example by {@link com.fasterxml.jackson.annotation.JsonTypeInfo}) * cannot be found (missing) or resolved (invalid class name, non-mappable id); * if enabled, an exception is thrown; if false, null value is used instead. *

* Feature is enabled by default so that exception is thrown for missing or invalid * type information. * * @since 2.2 */ FAIL_ON_INVALID_SUBTYPE(true), /** * Feature that determines what happens when reading JSON content into tree * ({@link com.fasterxml.jackson.core.TreeNode}) and a duplicate key * is encountered (property name that was already seen for the JSON Object). * If enabled, {@link JsonMappingException} will be thrown; if disabled, no exception * is thrown and the new (later) value overwrites the earlier value. *

* Note that this property does NOT affect other aspects of data-binding; that is, * no detection is done with respect to POJO properties or {@link java.util.Map} * keys. New features may be added to control additional cases. *

* Feature is disabled by default so that no exception is thrown. * * @since 2.3 */ FAIL_ON_READING_DUP_TREE_KEY(false), /** * Feature that determines what happens when a property that has been explicitly * marked as ignorable is encountered in input: if feature is enabled, * {@link JsonMappingException} is thrown; if false, property is quietly skipped. *

* Feature is disabled by default so that no exception is thrown. * * @since 2.3 */ FAIL_ON_IGNORED_PROPERTIES(false), /** * Feature that determines what happens if an Object Id reference is encountered * that does not refer to an actual Object with that id ("unresolved Object Id"): * either an exception is thrown (true), or a null object is used * instead (false). * Note that if this is set to false, no further processing is done; * specifically, if reference is defined via setter method, that method will NOT * be called. *

* Feature is enabled by default, so that unknown Object Ids will result in an * exception being thrown, at the end of deserialization. * * @since 2.5 */ FAIL_ON_UNRESOLVED_OBJECT_IDS(true), /** * Feature that determines what happens if one or more Creator properties (properties * bound to parameters of Creator method (constructor or static factory method)) * are missing value to bind to from content. * If enabled, such missing values result in a {@link JsonMappingException} being * thrown with information on the first one (by index) of missing properties. * If disabled, and if property is NOT marked as required, * missing Creator properties are filled * with null values provided by deserializer for the type of parameter * (usually null for Object types, and default value for primitives; but redefinable * via custom deserializers). *

* Note that having an injectable value counts as "not missing". *

* Feature is disabled by default, so that no exception is thrown for missing creator * property values, unless they are explicitly marked as `required`. * * @since 2.6 */ FAIL_ON_MISSING_CREATOR_PROPERTIES(false), /** * Feature that determines what happens if one or more Creator properties (properties * bound to parameters of Creator method (constructor or static factory method)) * are bound to null values - either from the JSON or as a default value. This * is useful if you want to avoid nulls in your codebase, and particularly useful * if you are using Java or Scala optionals for non-mandatory fields. * Feature is disabled by default, so that no exception is thrown for missing creator * property values, unless they are explicitly marked as `required`. * * @since 2.8 */ FAIL_ON_NULL_CREATOR_PROPERTIES(false), /** * Feature that determines what happens when a property annotated with * {@link com.fasterxml.jackson.annotation.JsonTypeInfo.As#EXTERNAL_PROPERTY} is missing, * but associated type id is available. If enabled, {@link JsonMappingException} is always * thrown when property value is missing (if type id does exist); * if disabled, exception is only thrown if property is marked as `required`. *

* Feature is enabled by default, so that exception is thrown when a subtype property is * missing. * * @since 2.9 */ FAIL_ON_MISSING_EXTERNAL_TYPE_ID_PROPERTY(true), /** * Feature that determines behaviour for data-binding after binding the root value. * If feature is enabled, one more call to * {@link com.fasterxml.jackson.core.JsonParser#nextToken} is made to ensure that * no more tokens are found (and if any is found, * {@link com.fasterxml.jackson.databind.exc.MismatchedInputException} is thrown); if * disabled, no further checks are made. *

* Feature could alternatively be called READ_FULL_STREAM, since it * effectively verifies that input stream contains only as much data as is needed * for binding the full value, and nothing more (except for possible ignorable * white space or comments, if supported by data format). *

* Feature is disabled by default (so that no check is made for possible trailing * token(s)) for backwards compatibility reasons. * * @since 2.9 */ FAIL_ON_TRAILING_TOKENS(false), /** * Feature that determines whether Jackson code should catch * and wrap {@link Exception}s (but never {@link Error}s!) * to add additional information about * location (within input) of problem or not. If enabled, * most exceptions will be caught and re-thrown (exception * specifically being that {@link java.io.IOException}s may be passed * as is, since they are declared as throwable); this can be * convenient both in that all exceptions will be checked and * declared, and so there is more contextual information. * However, sometimes calling application may just want "raw" * unchecked exceptions passed as is. *

* NOTE: most of the time exceptions that may or may not be wrapped are of * type {@link RuntimeException}: as mentioned earlier, various * {@link java.io.IOException}s (and in particular * {@link com.fasterxml.jackson.core.JacksonException}s) will * always be passed as-is. *

* Feature is enabled by default. */ WRAP_EXCEPTIONS(true), /* /****************************************************** /* Structural conversion features /****************************************************** */ /** * Feature that determines whether it is acceptable to coerce non-array * (in JSON) values to work with Java collection (arrays, java.util.Collection) * types. If enabled, collection deserializers will try to handle non-array * values as if they had "implicit" surrounding JSON array. * This feature is meant to be used for compatibility/interoperability reasons, * to work with packages (such as XML-to-JSON converters) that leave out JSON * array in cases where there is just a single element in array. *

* Feature is disabled by default. */ ACCEPT_SINGLE_VALUE_AS_ARRAY(false), /** * Feature that determines whether it is acceptable to coerce single value array (in JSON) * values to the corresponding value type. This is basically the opposite of the {@link #ACCEPT_SINGLE_VALUE_AS_ARRAY} * feature. If more than one value is found in the array, a JsonMappingException is thrown. *

* NOTE: only single wrapper Array is allowed: if multiple attempted, exception * will be thrown. * * Feature is disabled by default. * @since 2.4 */ UNWRAP_SINGLE_VALUE_ARRAYS(false), /** * Feature to allow "unwrapping" root-level JSON value, to match setting of * {@link SerializationFeature#WRAP_ROOT_VALUE} used for serialization. * Will verify that the root JSON value is a JSON Object, and that it has * a single property with expected root name. If not, a * {@link JsonMappingException} is thrown; otherwise value of the wrapped property * will be deserialized as if it was the root value. *

* Feature is disabled by default. */ UNWRAP_ROOT_VALUE(false), /* /****************************************************** /* Value conversion features /****************************************************** */ /** * Feature that can be enabled to allow JSON empty String * value ("") to be bound as `null` for POJOs and other structured * values ({@link java.util.Map}s, {@link java.util.Collection}s). * If disabled, standard POJOs can only be bound from JSON `null` or * JSON Object (standard meaning that no custom deserializers or * constructors are defined; both of which can add support for other * kinds of JSON values); if enabled, empty JSON String can be taken * to be equivalent of JSON null. *

* NOTE: this does NOT apply to scalar values such as booleans and numbers; * whether they can be coerced depends on * {@link MapperFeature#ALLOW_COERCION_OF_SCALARS}. *

* Feature is disabled by default. */ ACCEPT_EMPTY_STRING_AS_NULL_OBJECT(false), /** * Feature that can be enabled to allow empty JSON Array * value (that is, [ ]) to be bound to POJOs (and * with 2.9, other values too) as `null`. * If disabled, standard POJOs can only be bound from JSON `null` or * JSON Object (standard meaning that no custom deserializers or * constructors are defined; both of which can add support for other * kinds of JSON values); if enabled, empty JSON Array will be taken * to be equivalent of JSON null. *

* Feature is disabled by default. * * @since 2.5 */ ACCEPT_EMPTY_ARRAY_AS_NULL_OBJECT(false), /** * Feature that determines whether coercion from JSON floating point * number (anything with command (`.`) or exponent portion (`e` / `E')) * to an expected integral number (`int`, `long`, `java.lang.Integer`, `java.lang.Long`, * `java.math.BigDecimal`) is allowed or not. * If enabled, coercion truncates value; if disabled, a {@link JsonMappingException} * will be thrown. *

* Feature is enabled by default. * * @since 2.6 */ ACCEPT_FLOAT_AS_INT(true), /** * Feature that determines standard deserialization mechanism used for * Enum values: if enabled, Enums are assumed to have been serialized using * return value of Enum.toString(); * if disabled, return value of Enum.name() is assumed to have been used. *

* Note: this feature should usually have same value * as {@link SerializationFeature#WRITE_ENUMS_USING_TO_STRING}. *

* Feature is disabled by default. */ READ_ENUMS_USING_TO_STRING(false), /** * Feature that allows unknown Enum values to be parsed as {@code null} values. * If disabled, unknown Enum values will throw exceptions. *

* Note that in some cases this will effectively ignore unknown {@code Enum} values, * e.g. when the unknown values are used as keys of {@link java.util.EnumMap} * or values of {@link java.util.EnumSet}: this is because these data structures cannot * store {@code null} values. *

* Also note that this feature has lower precedence than * {@link DeserializationFeature#READ_UNKNOWN_ENUM_VALUES_USING_DEFAULT_VALUE}, * meaning this feature will work only if latter feature is disabled. *

* Feature is disabled by default. * * @since 2.0 */ READ_UNKNOWN_ENUM_VALUES_AS_NULL(false), /** * Feature that allows unknown Enum values to be ignored and replaced by a predefined value specified through * {@link com.fasterxml.jackson.annotation.JsonEnumDefaultValue @JsonEnumDefaultValue} annotation. * If disabled, unknown Enum values will throw exceptions. * If enabled, but no predefined default Enum value is specified, an exception will be thrown as well. *

* Note that this feature has higher precedence than {@link DeserializationFeature#READ_UNKNOWN_ENUM_VALUES_AS_NULL}. *

* Feature is disabled by default. * * @since 2.8 */ READ_UNKNOWN_ENUM_VALUES_USING_DEFAULT_VALUE(false), /** * Feature that controls whether numeric timestamp values are expected * to be written using nanosecond timestamps (enabled) or not (disabled), * if and only if datatype supports such resolution. * Only newer datatypes (such as Java8 Date/Time) support such resolution -- * older types (pre-Java8 java.util.Date etc) and Joda do not -- * and this setting has no effect on such types. *

* If disabled, standard millisecond timestamps are assumed. * This is the counterpart to {@link SerializationFeature#WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS}. *

* Feature is enabled by default, to support most accurate time values possible. * * @since 2.2 */ READ_DATE_TIMESTAMPS_AS_NANOSECONDS(true), /** * Feature that specifies whether context provided {@link java.util.TimeZone} * ({@link DeserializationContext#getTimeZone()} should be used to adjust Date/Time * values on deserialization, even if value itself contains timezone information. * If enabled, contextual TimeZone will essentially override any other * TimeZone information; if disabled, it will only be used if value itself does not * contain any TimeZone information. *

* Note that exact behavior depends on date/time types in question; and specifically * JDK type of {@link java.util.Date} does NOT have in-built timezone information * so this setting has no effect. * Further, while {@link java.util.Calendar} does have this information basic * JDK {@link java.text.SimpleDateFormat} is unable to retain parsed zone information, * and as a result, {@link java.util.Calendar} will always get context timezone * adjustment regardless of this setting. *

*

* Taking above into account, this feature is supported only by extension modules for * Joda and Java 8 date/time datatypes. * * @since 2.2 */ ADJUST_DATES_TO_CONTEXT_TIME_ZONE(true), /* /****************************************************** /* Other /****************************************************** */ /** * Feature that determines whether {@link ObjectReader} should * try to eagerly fetch necessary {@link JsonDeserializer} when * possible. This improves performance in cases where similarly * configured {@link ObjectReader} instance is used multiple * times; and should not significantly affect single-use cases. *

* Note that there should not be any need to normally disable this * feature: only consider that if there are actual perceived problems. *

* Feature is enabled by default. * * @since 2.1 */ EAGER_DESERIALIZER_FETCH(true) ; private final boolean _defaultState; private final int _mask; private DeserializationFeature(boolean defaultState) { _defaultState = defaultState; _mask = (1 << ordinal()); } @Override public boolean enabledByDefault() { return _defaultState; } @Override public int getMask() { return _mask; } @Override public boolean enabledIn(int flags) { return (flags & _mask) != 0; } }