com.alibaba.fastjson2.reader

Interface ObjectReader<T>

Type Parameters:

T - the type of objects that this ObjectReader can deserialize

All Known Subinterfaces:

ObjectDeserializer

All Known Implementing Classes:

ApacheLang3Support.PairReader, CollectionCodec, Fastjson1xReaderModule.JSONImpl, GeoJsonPointReader, GeoJsonPolygonReader, JavaBeanDeserializer, JdbcSupport.DateReader, JdbcSupport.TimeReader, JdbcSupport.TimestampReader, JodaSupport.ChronologyReader, JodaSupport.InstantReader, JodaSupport.LocalDateReader, JodaSupport.LocalDateTimeReader, MapDeserializer, ObjectArrayReader, ObjectArrayReaderMultiType, ObjectArrayTypedReader, ObjectDeserializerWrapper, ObjectReader1, ObjectReader10, ObjectReader11, ObjectReader12, ObjectReader2, ObjectReader3, ObjectReader4, ObjectReader5, ObjectReader6, ObjectReader7, ObjectReader8, ObjectReader9, ObjectReaderAdapter, ObjectReaderBean, ObjectReaderException, ObjectReaderImplAtomicReference, ObjectReaderImplBigDecimal, ObjectReaderImplBigInteger, ObjectReaderImplBitSet, ObjectReaderImplBoolean, ObjectReaderImplBoolValueArray, ObjectReaderImplByte, ObjectReaderImplCalendar, ObjectReaderImplCharacter, ObjectReaderImplCharValueArray, ObjectReaderImplClass, ObjectReaderImplCurrency, ObjectReaderImplDate, ObjectReaderImplDouble, ObjectReaderImplDoubleArray, ObjectReaderImplDoubleValueArray, ObjectReaderImplEnum, ObjectReaderImplField, ObjectReaderImplFloat, ObjectReaderImplFloatArray, ObjectReaderImplFloatValueArray, ObjectReaderImplFromBoolean, ObjectReaderImplFromInt, ObjectReaderImplFromLong, ObjectReaderImplFromString, ObjectReaderImplGenericArray, ObjectReaderImplHijrahDate, ObjectReaderImplInstant, ObjectReaderImplInt16Array, ObjectReaderImplInt16ValueArray, ObjectReaderImplInt32Array, ObjectReaderImplInt32ValueArray, ObjectReaderImplInt64, ObjectReaderImplInt64Array, ObjectReaderImplInt64ValueArray, ObjectReaderImplInt8Array, ObjectReaderImplInt8ValueArray, ObjectReaderImplInteger, ObjectReaderImplJapaneseDate, ObjectReaderImplJSONP, ObjectReaderImplList, ObjectReaderImplListInt64, ObjectReaderImplListStr, ObjectReaderImplLocalDate, ObjectReaderImplLocalDateTime, ObjectReaderImplLocale, ObjectReaderImplLocalTime, ObjectReaderImplMap, ObjectReaderImplMapEntry, ObjectReaderImplMapMultiValueType, ObjectReaderImplMapString, ObjectReaderImplMapTyped, ObjectReaderImplMethod, ObjectReaderImplMinguoDate, ObjectReaderImplMonthDay, ObjectReaderImplNumber, ObjectReaderImplNumberArray, ObjectReaderImplObject, ObjectReaderImplOffsetDateTime, ObjectReaderImplOffsetTime, ObjectReaderImplOptional, ObjectReaderImplOptionalDouble, ObjectReaderImplOptionalInt, ObjectReaderImplOptionalLong, ObjectReaderImplShort, ObjectReaderImplString, ObjectReaderImplStringArray, ObjectReaderImplThaiBuddhistDate, ObjectReaderImplUUID, ObjectReaderImplValue, ObjectReaderImplValueInt, ObjectReaderImplValueString, ObjectReaderImplYear, ObjectReaderImplYearMonth, ObjectReaderImplZonedDateTime, ObjectReaderInterface, ObjectReaderMisc, ObjectReaderNoneDefaultConstructor, ObjectReaderPrimitive, ObjectReaderRootName, ObjectReaderSeeAlso

public interface ObjectReader<T>

ObjectReader is responsible for deserializing JSON data into Java objects. It provides a set of methods for creating object instances, reading JSON data, and handling field mapping.

This interface supports various features including:

• Object creation with different parameter types
• JSON object and array reading
• Field mapping and value setting
• Auto-type support for polymorphic deserialization
• Custom feature configuration

Example usage:

 // Get an ObjectReader for a specific type
 ObjectReader<User> reader = JSONFactory.getDefaultObjectReaderProvider().getObjectReader(User.class);

 // Read from JSON string
 String jsonString = "{\"id\":1,\"name\":\"John\"}";
 User user = reader.readObject(JSONReader.of(jsonString));

 // Create instance with map data
 Map<String, Object> data = new HashMap<>();
 data.put("id", 1);
 data.put("name", "John");
 User user2 = reader.createInstance(data);
 

Since:

2.0.0

Field Summary

Fields

Modifier and Type	Field and Description
static long	HASH_TYPE
static java.lang.String	VALUE_NAME

Method Summary

Modifier and Type	Method and Description
default T	accept(T object, java.util.Map map, long features) Accepts field values from a map and populates the specified object instance.
default void	acceptExtra(java.lang.Object object, java.lang.String fieldName, java.lang.Object fieldValue) Accepts extra field data that is not mapped to any specific field in the object.
default void	acceptExtra(java.lang.Object object, java.lang.String fieldName, java.lang.Object fieldValue, long features) Accepts extra field data that is not mapped to any specific field in the object.
default ObjectReader	autoType(JSONReader.Context context, long typeHash) Resolves an ObjectReader for the specified type hash using the JSON reader context.
default ObjectReader	autoType(ObjectReaderProvider provider, long typeHash) Resolves an ObjectReader for the specified type hash using the ObjectReaderProvider.
default T	createInstance()
default T	createInstance(java.util.Collection collection)
default T	createInstance(java.util.Collection collection, JSONReader.Feature... features)
default T	createInstance(java.util.Collection collection, long features)
default T	createInstance(long features)
default T	createInstance(java.util.Map map, JSONReader.Feature... features) Creates an instance of the object type from a map of field values using the specified features.
default T	createInstance(java.util.Map map, long features)
default T	createInstanceNoneDefaultConstructor(java.util.Map<java.lang.Long,java.lang.Object> values) Creates an instance of the object type using a non-default constructor with the specified values.
default java.util.function.Function	getBuildFunction() Gets the build function used to construct the final object instance.
default long	getFeatures() Gets the features enabled by this ObjectReader.
default FieldReader	getFieldReader(long hashCode) Gets the FieldReader for the specified field hash code.
default FieldReader	getFieldReader(java.lang.String fieldName) Gets the FieldReader for the specified field name.
default FieldReader	getFieldReaderLCase(long hashCode) Gets the FieldReader for the specified field hash code, using lowercase matching.
default java.lang.Class<T>	getObjectClass() Gets the class of objects that this ObjectReader can deserialize.
default java.lang.String	getTypeKey() Gets the type key used for auto-type support.
default long	getTypeKeyHash() Gets the hash code of the type key used for auto-type support.
default T	readArrayMappingJSONBObject(JSONReader jsonReader, java.lang.reflect.Type fieldType, java.lang.Object fieldName, long features) Reads an object from JSONB format with array mapping.
default T	readArrayMappingObject(JSONReader jsonReader, java.lang.reflect.Type fieldType, java.lang.Object fieldName, long features) Reads an object from JSON format with array mapping.
default T	readJSONBObject(JSONReader jsonReader, java.lang.reflect.Type fieldType, java.lang.Object fieldName, long features) Reads an object from JSONB format.
default T	readObject(JSONReader jsonReader) Reads an object from the specified JSONReader.
default T	readObject(JSONReader jsonReader, long features) Reads an object from the specified JSONReader using the provided features.
T	readObject(JSONReader jsonReader, java.lang.reflect.Type fieldType, java.lang.Object fieldName, long features) Reads an object from the specified JSONReader with the given field type, field name, and features.
default T	readObject(java.lang.String str, JSONReader.Feature... features) Reads an object from the specified JSON string using the provided features.
default boolean	setFieldValue(java.lang.Object object, java.lang.String fieldName, long fieldNameHashCode, int value) Sets the value of a field in the specified object.
default boolean	setFieldValue(java.lang.Object object, java.lang.String fieldName, long fieldNameHashCode, long value) Sets the value of a field in the specified object.
default boolean	setFieldValue(java.lang.Object object, java.lang.String fieldName, java.lang.Object value) Sets the value of a field in the specified object.

Field Detail

HASH_TYPE

static final long HASH_TYPE

VALUE_NAME

static final java.lang.String VALUE_NAME

See Also:

Constant Field Values

Method Detail

createInstance

default T createInstance()

Returns:

T

Throws:

java.lang.UnsupportedOperationException - If the method is not overloaded or otherwise

createInstance

default T createInstance(long features)

Returns:

T

Throws:

java.lang.UnsupportedOperationException - If the method is not overloaded or otherwise

createInstance

default T createInstance(java.util.Collection collection)

Returns:

T

Throws:

java.lang.UnsupportedOperationException - If the method is not overloaded or otherwise

createInstance

default T createInstance(java.util.Collection collection,
                         JSONReader.Feature... features)

Returns:

T

Throws:

java.lang.UnsupportedOperationException - If the method is not overloaded or otherwise

createInstance

default T createInstance(java.util.Collection collection,
                         long features)

Returns:

T

Throws:

java.lang.UnsupportedOperationException - If the method is not overloaded or otherwise

acceptExtra

default void acceptExtra(java.lang.Object object,
                         java.lang.String fieldName,
                         java.lang.Object fieldValue)

Accepts extra field data that is not mapped to any specific field in the object. This method is called when deserializing JSON objects that contain fields not present in the target class.

Parameters:

object - the object being deserialized

fieldName - the name of the extra field

fieldValue - the value of the extra field

acceptExtra

default void acceptExtra(java.lang.Object object,
                         java.lang.String fieldName,
                         java.lang.Object fieldValue,
                         long features)

Accepts extra field data that is not mapped to any specific field in the object. This method is called when deserializing JSON objects that contain fields not present in the target class.

Parameters:

object - the object being deserialized

fieldName - the name of the extra field

fieldValue - the value of the extra field

features - the JSON reader features to use

createInstance

default T createInstance(java.util.Map map,
                         JSONReader.Feature... features)

Creates an instance of the object type from a map of field values using the specified features.

Parameters:

map - the map containing field names and values

features - the JSON reader features to use

Returns:

a new instance of the object populated with values from the map

createInstance

default T createInstance(java.util.Map map,
                         long features)

Returns:

T

Throws:

JSONException - If a suitable ObjectReader is not found

accept

default T accept(T object,
                 java.util.Map map,
                 long features)

Accepts field values from a map and populates the specified object instance.

Parameters:

object - the object instance to populate

map - the map containing field names and values

features - the JSON reader features to use

Returns:

the populated object instance

createInstanceNoneDefaultConstructor

default T createInstanceNoneDefaultConstructor(java.util.Map<java.lang.Long,java.lang.Object> values)

Creates an instance of the object type using a non-default constructor with the specified values.

Parameters:

values - the map of field hash codes to values

Returns:

a new instance of the object created with a non-default constructor

Throws:

java.lang.UnsupportedOperationException - if the method is not overloaded or otherwise

getFeatures

default long getFeatures()

Gets the features enabled by this ObjectReader.

Returns:

the enabled features as a bit mask

getTypeKey

default java.lang.String getTypeKey()

Gets the type key used for auto-type support. This key is used to identify the type information in JSON objects.

Returns:

the type key string

getTypeKeyHash

default long getTypeKeyHash()

Gets the hash code of the type key used for auto-type support.

Returns:

the hash code of the type key

getObjectClass

default java.lang.Class<T> getObjectClass()

Gets the class of objects that this ObjectReader can deserialize.

Returns:

the object class, or null if not specified

getFieldReader

default FieldReader getFieldReader(long hashCode)

Gets the FieldReader for the specified field hash code.

Parameters:

hashCode - the hash code of the field name

Returns:

the FieldReader for the field, or null if not found

getFieldReaderLCase

default FieldReader getFieldReaderLCase(long hashCode)

Gets the FieldReader for the specified field hash code, using lowercase matching.

Parameters:

hashCode - the hash code of the field name (lowercase)

Returns:

the FieldReader for the field, or null if not found

setFieldValue

default boolean setFieldValue(java.lang.Object object,
                              java.lang.String fieldName,
                              long fieldNameHashCode,
                              int value)

Sets the value of a field in the specified object.

Parameters:

object - the object in which to set the field value

fieldName - the name of the field to set

fieldNameHashCode - the hash code of the field name

value - the integer value to set

Returns:

true if the field was successfully set, false otherwise

setFieldValue

default boolean setFieldValue(java.lang.Object object,
                              java.lang.String fieldName,
                              long fieldNameHashCode,
                              long value)

Sets the value of a field in the specified object.

Parameters:

object - the object in which to set the field value

fieldName - the name of the field to set

fieldNameHashCode - the hash code of the field name

value - the long value to set

Returns:

true if the field was successfully set, false otherwise

getFieldReader

default FieldReader getFieldReader(java.lang.String fieldName)

Gets the FieldReader for the specified field name.

Parameters:

fieldName - the name of the field

Returns:

the FieldReader for the field, or null if not found

setFieldValue

default boolean setFieldValue(java.lang.Object object,
                              java.lang.String fieldName,
                              java.lang.Object value)

Sets the value of a field in the specified object.

Parameters:

object - the object in which to set the field value

fieldName - the name of the field to set

value - the object value to set

Returns:

true if the field was successfully set, false otherwise

getBuildFunction

default java.util.function.Function getBuildFunction()

Gets the build function used to construct the final object instance.

Returns:

the build function, or null if not specified

autoType

default ObjectReader autoType(JSONReader.Context context,
                              long typeHash)

Resolves an ObjectReader for the specified type hash using the JSON reader context.

Parameters:

context - the JSON reader context

typeHash - the hash code of the type name

Returns:

the ObjectReader for the type, or null if not found

autoType

default ObjectReader autoType(ObjectReaderProvider provider,
                              long typeHash)

Resolves an ObjectReader for the specified type hash using the ObjectReaderProvider.

Parameters:

provider - the ObjectReaderProvider

typeHash - the hash code of the type name

Returns:

the ObjectReader for the type, or null if not found

readJSONBObject

default T readJSONBObject(JSONReader jsonReader,
                          java.lang.reflect.Type fieldType,
                          java.lang.Object fieldName,
                          long features)

Reads an object from JSONB format.

Parameters:

jsonReader - the JSONReader to use for parsing

fieldType - the type of the field being read

fieldName - the name of the field being read

features - the features to use

Returns:

the deserialized object

Throws:

JSONException - if a suitable ObjectReader is not found

readArrayMappingJSONBObject

default T readArrayMappingJSONBObject(JSONReader jsonReader,
                                      java.lang.reflect.Type fieldType,
                                      java.lang.Object fieldName,
                                      long features)

Reads an object from JSONB format with array mapping.

Parameters:

jsonReader - the JSONReader to use for parsing

fieldType - the type of the field being read

fieldName - the name of the field being read

features - the features to use

Returns:

the deserialized object

Throws:

java.lang.UnsupportedOperationException - if the method is not overloaded or otherwise

readArrayMappingObject

default T readArrayMappingObject(JSONReader jsonReader,
                                 java.lang.reflect.Type fieldType,
                                 java.lang.Object fieldName,
                                 long features)

Reads an object from JSON format with array mapping.

Parameters:

jsonReader - the JSONReader to use for parsing

fieldType - the type of the field being read

fieldName - the name of the field being read

features - the features to use

Returns:

the deserialized object

Throws:

java.lang.UnsupportedOperationException - if the method is not overloaded or otherwise

readObject

default T readObject(java.lang.String str,
                     JSONReader.Feature... features)

Reads an object from the specified JSON string using the provided features.

Parameters:

str - the JSON string to parse

features - the JSON reader features to use

Returns:

the deserialized object

readObject

default T readObject(JSONReader jsonReader)

Reads an object from the specified JSONReader.

Parameters:

jsonReader - the JSONReader to use for parsing

Returns:

the deserialized object

readObject

default T readObject(JSONReader jsonReader,
                     long features)

Reads an object from the specified JSONReader using the provided features.

Parameters:

jsonReader - the JSONReader to use for parsing

features - the features to use

Returns:

the deserialized object

readObject

T readObject(JSONReader jsonReader,
             java.lang.reflect.Type fieldType,
             java.lang.Object fieldName,
             long features)

Reads an object from the specified JSONReader with the given field type, field name, and features.

Parameters:

jsonReader - the JSONReader to use for parsing

fieldType - the type of the field being read

fieldName - the name of the field being read

features - the features to use

Returns:

the deserialized object

Throws:

JSONException - if a suitable ObjectReader is not found