Class JavaType

  • Direct Known Subclasses:
    TypeBase

    public abstract class JavaType
    extends Object
    Base class for type token classes used both to contain information and as keys for deserializers.

    Instances can (only) be constructed by TypeFactory.

    • Field Detail

      • _class

        protected final Class<?> _class
        This is the nominal type-erased Class that would be close to the type represented (but not exactly type, due to type erasure: type instance may have more information on this). May be an interface or abstract class, so instantiation may not be possible.
      • _hashCode

        protected final int _hashCode
      • _valueHandler

        protected Object _valueHandler
        Optional handler (codec) that can be attached to indicate what to use for handling (serializing, deserializing) values of this specific type.

        Note: untyped (i.e. caller has to cast) because it is used for different kinds of handlers, with unrelated types.

        TODO: make final and possible promote to sub-classes

        Since:
        1.3
      • _typeHandler

        protected Object _typeHandler
        Optional handler that can be attached to indicate how to handle additional type metadata associated with this type.

        Note: untyped (i.e. caller has to cast) because it is used for different kinds of handlers, with unrelated types.

        TODO: make final and possible promote to sub-classes

        Since:
        1.5
    • Constructor Detail

      • JavaType

        protected JavaType​(Class<?> raw,
                           int additionalHash)
        Parameters:
        raw - "Raw" (type-erased) class for this type
        additionalHash - Additional hash code to use, in addition to hash code of the class name
    • Method Detail

      • withTypeHandler

        public abstract JavaType withTypeHandler​(Object h)
        "Copy method" that will construct a new instance that is identical to this instance, except that it will have specified type handler assigned.
        Returns:
        Newly created type instance
        Since:
        1.7
      • withContentTypeHandler

        public abstract JavaType withContentTypeHandler​(Object h)
        "Copy method" that will construct a new instance that is identical to this instance, except that its content type will have specified type handler assigned.
        Returns:
        Newly created type instance
        Since:
        1.7
      • withValueHandler

        public JavaType withValueHandler​(Object h)
        Since:
        1.9
      • withContentValueHandler

        public JavaType withContentValueHandler​(Object h)
        Since:
        1.9
      • setValueHandler

        @Deprecated
        public void setValueHandler​(Object h)
        Deprecated.
        Since 1.9, should not be used; instead, use withContentTypeHandler and withContentValueHandler methods.
        Method for assigning handler to associate with this type; or if null passed, to remove such assignment
        Since:
        1.3
      • narrowBy

        public JavaType narrowBy​(Class<?> subclass)
        Method that can be called to do a "narrowing" conversions; that is, to return a type with a raw class that is assignable to the raw class of this type. If this is not possible, an IllegalArgumentException is thrown. If class is same as the current raw class, instance itself is returned.
      • forcedNarrowBy

        public JavaType forcedNarrowBy​(Class<?> subclass)
        More efficient version of narrowBy(java.lang.Class<?>), called by internal framework in cases where compatibility checks are to be skipped.
        Since:
        1.5
      • widenBy

        public JavaType widenBy​(Class<?> superclass)
        Method that can be called to do a "widening" conversions; that is, to return a type with a raw class that could be assigned from this type. If such conversion is not possible, an IllegalArgumentException is thrown. If class is same as the current raw class, instance itself is returned.
      • _narrow

        protected abstract JavaType _narrow​(Class<?> subclass)
      • narrowContentsBy

        public abstract JavaType narrowContentsBy​(Class<?> contentClass)
      • widenContentsBy

        public abstract JavaType widenContentsBy​(Class<?> contentClass)
        Since:
        1.8
      • getRawClass

        public final Class<?> getRawClass()
      • hasRawClass

        public final boolean hasRawClass​(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.
      • isAbstract

        public boolean isAbstract()
      • isConcrete

        public boolean isConcrete()
        Since:
        1.3
      • isThrowable

        public boolean isThrowable()
      • isArrayType

        public boolean isArrayType()
      • isEnumType

        public final boolean isEnumType()
      • isInterface

        public final boolean isInterface()
      • isPrimitive

        public final boolean isPrimitive()
      • isFinal

        public final boolean isFinal()
      • isContainerType

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

        public boolean isCollectionLikeType()
        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)
        Since:
        1.8
      • isMapLikeType

        public boolean isMapLikeType()
        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)
        Since:
        1.8
      • hasGenericTypes

        public 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).
        Since:
        1.6
      • getKeyType

        public JavaType getKeyType()
        Method for accessing key type for this type, assuming type has such a concept (only Map types do)
      • getContentType

        public 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)
      • containedTypeCount

        public int containedTypeCount()
        Method for checking how many contained types this type has. Contained types are usually generic types, so that generic Maps have 2 contained types.
        Since:
        1.5
      • containedType

        public JavaType containedType​(int index)
        Method for accessing definitions of contained ("child") types.
        Parameters:
        index - Index of contained type to return
        Returns:
        Contained type at index, or null if no such type exists (no exception thrown)
        Since:
        1.5
      • containedTypeName

        public String containedTypeName​(int index)
        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.
        Parameters:
        index - Index of contained type to return
        Returns:
        Contained type at index, or null if no such type exists (no exception thrown)
        Since:
        1.5
      • getValueHandler

        public <T> T getValueHandler()
        Method for accessing value handler associated with this type, if any
        Since:
        1.3
      • getTypeHandler

        public <T> T getTypeHandler()
        Method for accessing type handler associated with this type, if any
        Since:
        1.5
      • toCanonical

        public abstract String toCanonical()
        Method that can be used to serialize type into form from which it can be fully deserialized from at a later point (using TypeFactory from mapper package). For simple types this is same as calling Class.getName(), but for structured types it may additionally contain type information about contents.
        Since:
        1.5
      • getGenericSignature

        public 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)
        Since:
        1.6
      • getGenericSignature

        public abstract StringBuilder getGenericSignature​(StringBuilder sb)
        Parameters:
        sb - StringBuilder to append signature to
        Returns:
        StringBuilder that was passed in; returned to allow call chaining
        Since:
        1.6
      • getErasedSignature

        public 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.
        Since:
        1.6
      • getErasedSignature

        public abstract StringBuilder getErasedSignature​(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
        Since:
        1.6
      • isTypeOrSubTypeOf

        public final boolean isTypeOrSubTypeOf​(Class<?> clz)
      • _assertSubclass

        protected void _assertSubclass​(Class<?> subclass,
                                       Class<?> superClass)
      • equals

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

        public final int hashCode()
        Overrides:
        hashCode in class Object