Class JavaType

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.reflect.Type
    Direct Known Subclasses:
    TypeBase

    public abstract class JavaType
    extends ResolvedType
    implements java.io.Serializable, java.lang.reflect.Type
    Base class for type token classes used both to contain information and as keys for deserializers.

    Instances can (only) be constructed by com.fasterxml.jackson.databind.type.TypeFactory.

    Since 2.2 this implements Type to allow it to be pushed through interfaces that only expose that type.

    See Also:
    Serialized Form
    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      abstract JavaType containedType​(int index)
      Method for accessing definitions of contained ("child") types.
      abstract int containedTypeCount()
      Method for checking how many contained types this type has.
      abstract java.lang.String containedTypeName​(int index)
      Deprecated.
      JavaType containedTypeOrUnknown​(int index)
      Convenience method that is functionally same as: JavaType t = containedType(index); if (t == null) { t = TypeFactory.unknownType(); } and typically used to eliminate need for null checks for common case where we just want to check if containedType is available first; and if not, use "unknown type" (which translates to java.lang.Object basically).
      abstract boolean equals​(java.lang.Object o)  
      abstract JavaType findSuperType​(java.lang.Class<?> erasedTarget)
      Method that may be called to find representation of given type within type hierarchy of this type: either this type (if this type has given erased type), one of its supertypes that has the erased types, or null if target is neither this type or any of its supertypes.
      abstract JavaType[] findTypeParameters​(java.lang.Class<?> expType)
      Method that may be used to find paramaterization this type has for given type-erased generic target type.
      JavaType forcedNarrowBy​(java.lang.Class<?> subclass)
      Deprecated.
      abstract TypeBindings getBindings()  
      JavaType getContentType()
      Method for accessing content type of this type, if type has such a thing: simple types do not, structured types do (like arrays, Collections and Maps)
      java.lang.Object getContentTypeHandler()
      Internal accessor that should not be used by any code outside of jackson-databind: only used internally by databind.
      java.lang.Object getContentValueHandler()
      Internal accessor that should not be used by any code outside of jackson-databind: only used internally by databind.
      java.lang.String getErasedSignature()
      Method for accessing signature without generic type information, in form compatible with all versions of JVM, and specifically used for type descriptions when generating byte code.
      abstract java.lang.StringBuilder getErasedSignature​(java.lang.StringBuilder sb)
      Method for accessing signature without generic type information, in form compatible with all versions of JVM, and specifically used for type descriptions when generating byte code.
      java.lang.String getGenericSignature()
      Method for accessing signature that contains generic type information, in form compatible with JVM 1.5 as per JLS.
      abstract java.lang.StringBuilder getGenericSignature​(java.lang.StringBuilder sb)  
      abstract java.util.List<JavaType> getInterfaces()
      Accessor for finding fully resolved interfaces this type implements, if any; empty array if none.
      JavaType getKeyType()
      Method for accessing key type for this type, assuming type has such a concept (only Map types do)
      java.lang.Class<?> getParameterSource()
      Deprecated.
      java.lang.Class<?> getRawClass()  
      JavaType getReferencedType()
      Method for accessing type of value that instances of this type references, if any.
      abstract JavaType getSuperClass()
      Accessor for finding fully resolved parent class of this type, if it has one; null if not.
      <T> T getTypeHandler()
      Internal accessor that should not be used by any code outside of jackson-databind: only used internally by databind.
      <T> T getValueHandler()
      Internal accessor that should not be used by any code outside of jackson-databind: only used internally by databind.
      boolean hasContentType()
      Accessor that allows determining whether getContentType() should return a non-null value (that is, there is a "content type") or not.
      boolean hasGenericTypes()
      Method that can be used to find out if the type directly declares generic parameters (for its direct super-class and/or super-interfaces).
      boolean hasHandlers()
      Helper method that checks whether this type, or its (optional) key or content type has getValueHandler() or getTypeHandler(); that is, are there any non-standard handlers associated with this type object.
      int hashCode()  
      boolean hasRawClass​(java.lang.Class<?> clz)
      Method that can be used to check whether this type has specified Class as its type erasure.
      boolean hasValueHandler()  
      boolean isAbstract()  
      boolean isArrayType()  
      boolean isCollectionLikeType()  
      boolean isConcrete()
      Convenience method for checking whether underlying Java type is a concrete class or not: abstract classes and interfaces are not.
      abstract boolean isContainerType()  
      boolean isEnumImplType()
      Similar to isEnumType() except does NOT return true for Enum (since that is not Enum implementation type).
      boolean isEnumType()
      Method that basically does equivalent of:
      boolean isFinal()  
      boolean isInterface()  
      boolean isJavaLangObject()
      Convenience method, short-hand for getRawClass() == Object.class and used to figure if we basically have "untyped" type object.
      boolean isMapLikeType()  
      boolean isPrimitive()  
      boolean isRecordType()  
      boolean isThrowable()  
      boolean isTypeOrSubTypeOf​(java.lang.Class<?> clz)  
      boolean isTypeOrSuperTypeOf​(java.lang.Class<?> clz)  
      abstract JavaType refine​(java.lang.Class<?> rawType, TypeBindings bindings, JavaType superClass, JavaType[] superInterfaces)
      Mutant factory method that will try to create and return a sub-type instance for known parameterized types; for other types will return `null` to indicate that no just refinement makes necessary sense, without trying to detect special status through implemented interfaces.
      abstract java.lang.String toString()  
      boolean useStaticType()
      Accessor for checking whether handlers for dealing with values of this type should use static typing (as opposed to dynamic typing).
      abstract JavaType withContentType​(JavaType contentType)
      Mutant factory method that may be called on structured types that have a so-called content type (element of arrays, value type of Maps, referenced type of referential types), and will construct a new instance that is identical to this instance, except that it has specified content type, instead of current one.
      abstract JavaType withContentTypeHandler​(java.lang.Object h)
      Internal method that should not be used by any code outside of jackson-databind: only used internally by databind.
      abstract JavaType withContentValueHandler​(java.lang.Object h)
      Internal method that should not be used by any code outside of jackson-databind: only used internally by databind.
      JavaType withHandlersFrom​(JavaType src)
      Internal method that should not be used by any code outside of jackson-databind: only used internally by databind.
      abstract JavaType withStaticTyping()
      Method that can be called to get a type instance that indicates that values of the type should be handled using "static typing" for purposes of serialization (as opposed to "dynamic" aka runtime typing): meaning that no runtime information is needed for determining serializers to use.
      abstract JavaType withTypeHandler​(java.lang.Object h)
      Internal method that should not be used by any code outside of jackson-databind: only used internally by databind.
      abstract JavaType withValueHandler​(java.lang.Object h)
      Internal method that should not be used by any code outside of jackson-databind: only used internally by databind.
      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, wait, wait, wait
      • Methods inherited from interface java.lang.reflect.Type

        getTypeName
    • Method Detail

      • withContentType

        public abstract JavaType withContentType​(JavaType contentType)
        Mutant factory method that may be called on structured types that have a so-called content type (element of arrays, value type of Maps, referenced type of referential types), and will construct a new instance that is identical to this instance, except that it has specified content type, instead of current one. If content type is already set to given type, this is returned. If type does not have a content type (which is the case with SimpleType), IllegalArgumentException will be thrown.
        Returns:
        Newly created type instance
        Since:
        2.7
      • withStaticTyping

        public abstract JavaType withStaticTyping()
        Method that can be called to get a type instance that indicates that values of the type should be handled using "static typing" for purposes of serialization (as opposed to "dynamic" aka runtime typing): meaning that no runtime information is needed for determining serializers to use. The main use case is to allow forcing of specific root value serialization type, and specifically in resolving serializers for contained types (element types for arrays, Collections and Maps).
        Since:
        2.2
      • withTypeHandler

        public abstract JavaType withTypeHandler​(java.lang.Object h)
        Internal method that should not be used by any code outside of jackson-databind: only used internally by databind. May be removed from Jackson 3.0.

        This mutant factory method will construct a new instance that is identical to this instance, except that it will have specified type handler assigned.

        Parameters:
        h - Handler to pass to new instance created
        Returns:
        Newly created type instance with same type information, specified handler
      • withContentTypeHandler

        public abstract JavaType withContentTypeHandler​(java.lang.Object h)
        Internal method that should not be used by any code outside of jackson-databind: only used internally by databind. May be removed from Jackson 3.0.

        This mutant factory method will construct a new instance that is identical to this instance, except that it will have specified content type (element type for arrays, value type for Maps and so forth) handler assigned.

        Parameters:
        h - Handler to pass to new instance created
        Returns:
        Newly created type instance with same type information, specified handler
      • withValueHandler

        public abstract JavaType withValueHandler​(java.lang.Object h)
        Internal method that should not be used by any code outside of jackson-databind: only used internally by databind. May be removed from Jackson 3.0.

        This mutant factory method will construct a new instance that is identical to this instance, except that it will have specified value handler assigned.

        Parameters:
        h - Handler to pass to new instance created
        Returns:
        Newly created type instance with same type information, specified handler
      • withContentValueHandler

        public abstract JavaType withContentValueHandler​(java.lang.Object h)
        Internal method that should not be used by any code outside of jackson-databind: only used internally by databind. May be removed from Jackson 3.0.

        Mutant factory method that will construct a new instance that is identical to this instance, except that it will have specified content value handler assigned.

        Parameters:
        h - Handler to pass to new instance created
        Returns:
        Newly created type instance with same type information, specified handler
      • withHandlersFrom

        public JavaType withHandlersFrom​(JavaType src)
        Internal method that should not be used by any code outside of jackson-databind: only used internally by databind. May be removed from Jackson 3.0.

        Mutant factory method that will try to copy handlers that the specified source type instance had, if any; this must be done recursively where necessary (as content types may be structured).

        Since:
        2.8.4
      • refine

        public abstract JavaType refine​(java.lang.Class<?> rawType,
                                        TypeBindings bindings,
                                        JavaType superClass,
                                        JavaType[] superInterfaces)
        Mutant factory method that will try to create and return a sub-type instance for known parameterized types; for other types will return `null` to indicate that no just refinement makes necessary sense, without trying to detect special status through implemented interfaces.
        Since:
        2.7
      • forcedNarrowBy

        @Deprecated
        public JavaType forcedNarrowBy​(java.lang.Class<?> subclass)
        Deprecated.
        Legacy method used for forcing sub-typing of this type into type specified by specific type erasure. Deprecated as of 2.7 as such specializations really ought to go through TypeFactory, not directly via JavaType.
        Since:
        2.7
      • getRawClass

        public final java.lang.Class<?> getRawClass()
        Specified by:
        getRawClass in class ResolvedType
        Returns:
        Type-erased Class of resolved type
      • hasRawClass

        public final boolean hasRawClass​(java.lang.Class<?> clz)
        Method that can be used to check whether this type has specified Class as its type erasure. Put another way, returns true if instantiation of this Type is given (type-erased) Class.
        Specified by:
        hasRawClass in class ResolvedType
      • isTypeOrSubTypeOf

        public final boolean isTypeOrSubTypeOf​(java.lang.Class<?> clz)
        Since:
        2.6
      • isTypeOrSuperTypeOf

        public final boolean isTypeOrSuperTypeOf​(java.lang.Class<?> clz)
        Since:
        2.9
      • isConcrete

        public boolean isConcrete()
        Convenience method for checking whether underlying Java type is a concrete class or not: abstract classes and interfaces are not.
        Specified by:
        isConcrete in class ResolvedType
      • isEnumType

        public final boolean isEnumType()
        Method that basically does equivalent of:
          Enum.class.isAssignableFrom(getRawClass())
        
        that is, return true if the underlying type erased class is Enum or one its subtypes (Enum implementations).
        Specified by:
        isEnumType in class ResolvedType
      • isEnumImplType

        public final boolean isEnumImplType()
        Similar to isEnumType() except does NOT return true for Enum (since that is not Enum implementation type).
        Since:
        2.11
      • isRecordType

        public final boolean isRecordType()
        Since:
        2.12
      • isContainerType

        public abstract boolean isContainerType()
        Specified by:
        isContainerType in class ResolvedType
        Returns:
        True if type represented is a container type; this includes array, Map and Collection types.
      • isCollectionLikeType

        public boolean isCollectionLikeType()
        Specified by:
        isCollectionLikeType in class ResolvedType
        Returns:
        True if type is either true Collection type, or something similar (meaning it has at least one type parameter, which describes type of contents)
      • isMapLikeType

        public boolean isMapLikeType()
        Specified by:
        isMapLikeType in class ResolvedType
        Returns:
        True if type is either true Map type, or something similar (meaning it has at least two type parameter; first one describing key type, second value type)
      • isJavaLangObject

        public final boolean isJavaLangObject()
        Convenience method, short-hand for getRawClass() == Object.class and used to figure if we basically have "untyped" type object.
        Since:
        2.5
      • useStaticType

        public final boolean useStaticType()
        Accessor for checking whether handlers for dealing with values of this type should use static typing (as opposed to dynamic typing). Note that while value of 'true' does mean that static typing is to be used, value of 'false' may still be overridden by other settings.
        Since:
        2.2
      • hasGenericTypes

        public boolean hasGenericTypes()
        Description copied from class: ResolvedType
        Method that can be used to find out if the type directly declares generic parameters (for its direct super-class and/or super-interfaces).
        Specified by:
        hasGenericTypes in class ResolvedType
        Returns:
        True if this type has generic type parameters, false if not
      • getKeyType

        public JavaType getKeyType()
        Description copied from class: ResolvedType
        Method for accessing key type for this type, assuming type has such a concept (only Map types do)
        Specified by:
        getKeyType in class ResolvedType
        Returns:
        Key type of this type, if any; null if none
      • getContentType

        public JavaType getContentType()
        Description copied from class: ResolvedType
        Method for accessing content type of this type, if type has such a thing: simple types do not, structured types do (like arrays, Collections and Maps)
        Specified by:
        getContentType in class ResolvedType
        Returns:
        Content type of this type, if any; null if none
      • getReferencedType

        public JavaType getReferencedType()
        Description copied from class: ResolvedType
        Method for accessing type of value that instances of this type references, if any.
        Specified by:
        getReferencedType in class ResolvedType
        Returns:
        Referenced type, if any; null if not.
      • containedTypeCount

        public abstract int containedTypeCount()
        Description copied from class: ResolvedType
        Method for checking how many contained types this type has. Contained types are usually generic types, so that generic Maps have 2 contained types.
        Specified by:
        containedTypeCount in class ResolvedType
        Returns:
        Number of contained types that may be accessed
      • containedType

        public abstract JavaType containedType​(int index)
        Description copied from class: ResolvedType
        Method for accessing definitions of contained ("child") types.
        Specified by:
        containedType in class ResolvedType
        Parameters:
        index - Index of contained type to return
        Returns:
        Contained type at index, or null if no such type exists (no exception thrown)
      • containedTypeName

        @Deprecated
        public abstract java.lang.String containedTypeName​(int index)
        Deprecated.
        Description copied from class: ResolvedType
        Method for accessing name of type variable in indicated position. If no name is bound, will use placeholders (derived from 0-based index); if no type variable or argument exists with given index, null is returned.
        Specified by:
        containedTypeName in class ResolvedType
        Parameters:
        index - Index of contained type to return
        Returns:
        Contained type at index, or null if no such type exists (no exception thrown)
      • getParameterSource

        @Deprecated
        public java.lang.Class<?> getParameterSource()
        Deprecated.
        Overrides:
        getParameterSource in class ResolvedType
        Returns:
        Type-erased class of something not usable at this point
      • containedTypeOrUnknown

        public JavaType containedTypeOrUnknown​(int index)
        Convenience method that is functionally same as: JavaType t = containedType(index); if (t == null) { t = TypeFactory.unknownType(); } and typically used to eliminate need for null checks for common case where we just want to check if containedType is available first; and if not, use "unknown type" (which translates to java.lang.Object basically).
        Since:
        2.5
      • getBindings

        public abstract TypeBindings getBindings()
        Since:
        2.7
      • findSuperType

        public abstract JavaType findSuperType​(java.lang.Class<?> erasedTarget)
        Method that may be called to find representation of given type within type hierarchy of this type: either this type (if this type has given erased type), one of its supertypes that has the erased types, or null if target is neither this type or any of its supertypes.
        Since:
        2.7
      • getSuperClass

        public abstract JavaType getSuperClass()
        Accessor for finding fully resolved parent class of this type, if it has one; null if not.
        Since:
        2.7
      • getInterfaces

        public abstract java.util.List<JavaType> getInterfaces()
        Accessor for finding fully resolved interfaces this type implements, if any; empty array if none.
        Since:
        2.7
      • findTypeParameters

        public abstract JavaType[] findTypeParameters​(java.lang.Class<?> expType)
        Method that may be used to find paramaterization this type has for given type-erased generic target type.
        Since:
        2.7
      • getValueHandler

        public <T> T getValueHandler()
        Internal accessor that should not be used by any code outside of jackson-databind: only used internally by databind. May be removed from Jackson 3.0.
        Returns:
        Value handler associated with this type, if any.
      • getTypeHandler

        public <T> T getTypeHandler()
        Internal accessor that should not be used by any code outside of jackson-databind: only used internally by databind. May be removed from Jackson 3.0.
        Returns:
        Type handler associated with this type, if any.
      • getContentValueHandler

        public java.lang.Object getContentValueHandler()
        Internal accessor that should not be used by any code outside of jackson-databind: only used internally by databind. May be removed from Jackson 3.0.
        Returns:
        Content value handler associated with this type, if any.
        Since:
        2.7
      • getContentTypeHandler

        public java.lang.Object getContentTypeHandler()
        Internal accessor that should not be used by any code outside of jackson-databind: only used internally by databind. May be removed from Jackson 3.0.
        Returns:
        Content type handler associated with this type, if any.
        Since:
        2.7
      • hasValueHandler

        public boolean hasValueHandler()
        Since:
        2.6
      • hasHandlers

        public boolean hasHandlers()
        Helper method that checks whether this type, or its (optional) key or content type has getValueHandler() or getTypeHandler(); that is, are there any non-standard handlers associated with this type object.
        Since:
        2.8
      • getGenericSignature

        public java.lang.String getGenericSignature()
        Method for accessing signature that contains generic type information, in form compatible with JVM 1.5 as per JLS. It is a superset of getErasedSignature(), in that generic information can be automatically removed if necessary (just remove outermost angle brackets along with content inside)
      • getGenericSignature

        public abstract java.lang.StringBuilder getGenericSignature​(java.lang.StringBuilder sb)
        Parameters:
        sb - StringBuilder to append signature to
        Returns:
        StringBuilder that was passed in; returned to allow call chaining
      • getErasedSignature

        public java.lang.String getErasedSignature()
        Method for accessing signature without generic type information, in form compatible with all versions of JVM, and specifically used for type descriptions when generating byte code.
      • getErasedSignature

        public abstract java.lang.StringBuilder getErasedSignature​(java.lang.StringBuilder sb)
        Method for accessing signature without generic type information, in form compatible with all versions of JVM, and specifically used for type descriptions when generating byte code.
        Parameters:
        sb - StringBuilder to append signature to
        Returns:
        StringBuilder that was passed in; returned to allow call chaining
      • toString

        public abstract java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • equals

        public abstract boolean equals​(java.lang.Object o)
        Overrides:
        equals in class java.lang.Object
      • hashCode

        public final int hashCode()
        Overrides:
        hashCode in class java.lang.Object