org.codehaus.jackson.type
Class JavaType

java.lang.Object
  extended by org.codehaus.jackson.type.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 Summary
protected  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).
protected  int _hashCode
           
protected  Object _typeHandler
          Optional handler that can be attached to indicate how to handle additional type metadata associated with this type.
protected  Object _valueHandler
          Optional handler (codec) that can be attached to indicate what to use for handling (serializing, deserializing) values of this specific type.
 
Constructor Summary
protected JavaType(Class<?> clz, int hash)
           
 
Method Summary
protected  void _assertSubclass(Class<?> subclass, Class<?> superClass)
           
protected abstract  JavaType _narrow(Class<?> subclass)
           
protected  JavaType _widen(Class<?> superclass)
           Default implementation is just to call _narrow(java.lang.Class), since underlying type construction is usually identical
 JavaType containedType(int index)
          Method for accessing definitions of contained ("child") types.
 int containedTypeCount()
          Method for checking how many contained types this type has.
 String containedTypeName(int index)
          Method for accessing name of type variable in indicated position.
abstract  boolean equals(Object o)
           
 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.
 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)
 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  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.
 String getGenericSignature()
          Method for accessing signature that contains generic type information, in form compatible with JVM 1.5 as per JLS.
abstract  StringBuilder getGenericSignature(StringBuilder sb)
           
 JavaType getKeyType()
          Method for accessing key type for this type, assuming type has such a concept (only Map types do)
 Class<?> getRawClass()
           
<T> T
getTypeHandler()
          Method for accessing type handler associated with this type, if any
<T> T
getValueHandler()
          Method for accessing value handler associated with this type, if any
 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).
 int hashCode()
           
 boolean hasRawClass(Class<?> clz)
          Method that can be used to check whether this type has specified Class as its type erasure.
 boolean isAbstract()
           
 boolean isArrayType()
           
 boolean isCollectionLikeType()
           
 boolean isConcrete()
           
abstract  boolean isContainerType()
           
 boolean isEnumType()
           
 boolean isFinal()
           
 boolean isInterface()
           
 boolean isMapLikeType()
           
 boolean isPrimitive()
           
 boolean isThrowable()
           
 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.
abstract  JavaType narrowContentsBy(Class<?> contentClass)
           
 void setTypeHandler(Object h)
          Deprecated. Used withTypeHandler(java.lang.Object) instead -- this method is dangerous as it changes state, whereas all other functionality is stateless
 void setValueHandler(Object h)
          Method for assigning handler to associate with this type; or if null passed, to remove such assignment
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).
abstract  String toString()
           
 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.
abstract  JavaType widenContentsBy(Class<?> contentClass)
           
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.
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.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

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.

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.

Since:
1.5
Constructor Detail

JavaType

protected JavaType(Class<?> clz,
                   int hash)
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

narrowBy

public final 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 final 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 final 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)

_widen

protected JavaType _widen(Class<?> superclass)

Default implementation is just to call _narrow(java.lang.Class), since underlying type construction is usually identical


narrowContentsBy

public abstract JavaType narrowContentsBy(Class<?> contentClass)

widenContentsBy

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

setValueHandler

public void setValueHandler(Object h)
Method for assigning handler to associate with this type; or if null passed, to remove such assignment

Since:
1.3

setTypeHandler

@Deprecated
public void setTypeHandler(Object h)
Deprecated. Used withTypeHandler(java.lang.Object) instead -- this method is dangerous as it changes state, whereas all other functionality is stateless

Method for assigning type handler to associate with this type; or if null passed, to remove such assignment

Since:
1.5

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

_assertSubclass

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

toString

public abstract String toString()
Overrides:
toString in class Object

equals

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

hashCode

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