# Package com.fasterxml.jackson.core.type

Contains classes needed for type introspection, mostly used by data binding functionality.

See: Description

Class Summary
Class | Description
--- | ---
ResolvedType | Type abstraction that represents Java type that has been resolved (i.e.
TypeReference<T> | This generic abstract class is used for obtaining full generics type information by sub-classing; it must be converted to `ResolvedType` implementation (implemented by `JavaType` from "databind" bundle) to be used.
WritableTypeId | This is a simple value class used between core streaming and higher level databinding to pass information about type ids to write.

Enum Summary
Enum | Description
--- | ---
WritableTypeId.Inclusion | Enumeration of values that matches enum `As` from annotation `JsonTypeInfo`: separate definition to avoid dependency between streaming core and annotations packages; also allows more flexibility in case new values needed at this level of internal API.

## Package com.fasterxml.jackson.core.type Description

Contains classes needed for type introspection, mostly used by data binding functionality. Most of this functionality is needed to properly handled generic types, and to simplify and unify processing of things Jackson needs to determine how contained types (of `Collection` and `Map` classes) are to be handled.

With 2.9, an additional type (`WritableTypeId`) was added to help handling of type identifiers needed to support polymorphic type serialization, deserialization.