org.codehaus.jackson.map.module
Class SimpleAbstractTypeResolver

java.lang.Object
  extended by org.codehaus.jackson.map.AbstractTypeResolver
      extended by org.codehaus.jackson.map.module.SimpleAbstractTypeResolver

public class SimpleAbstractTypeResolver
extends AbstractTypeResolver

Simple AbstractTypeResolver implementation, which is based on static mapping from abstract super types into sub types (concrete or abstract), but retaining generic parameterization. Can be used for things like specifying which implementation of Collection to use:

  SimpleAbstractTypeResolver resolver = new SimpleAbstractTypeResolver();
  // To make all properties declared as Collection, List, to LinkedList
  resolver.addMapping(Collection.class, LinkedList.class);
  resolver.addMapping(List.class, LinkedList.class);
Can also be used as an alternative to per-class annotations when defining concrete implementations; however, only works with abstract types (since this is only called for abstract types)

Since:
1.8

Field Summary
protected  HashMap<ClassKey,Class<?>> _mappings
          Mappings from super types to subtypes
 
Constructor Summary
SimpleAbstractTypeResolver()
           
 
Method Summary
<T> SimpleAbstractTypeResolver
addMapping(Class<T> superType, Class<? extends T> subType)
          Method for adding a mapping from super type to specific subtype.
 JavaType findTypeMapping(DeserializationConfig config, JavaType type)
          Try to locate a subtype for given abstract type, to either resolve to a concrete type, or at least to a more-specific (and hopefully supported) abstract type, one which may have registered deserializers.
 JavaType resolveAbstractType(DeserializationConfig config, JavaType type)
          Method called to try to resolve an abstract type into concrete type (usually for purposes of deserializing), when no concrete implementation was found.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

_mappings

protected final HashMap<ClassKey,Class<?>> _mappings
Mappings from super types to subtypes

Constructor Detail

SimpleAbstractTypeResolver

public SimpleAbstractTypeResolver()
Method Detail

addMapping

public <T> SimpleAbstractTypeResolver addMapping(Class<T> superType,
                                                 Class<? extends T> subType)
Method for adding a mapping from super type to specific subtype. Arguments will be checked by method, to ensure that superType is abstract (since resolver is never called for concrete classes); as well as to ensure that there is supertype/subtype relationship (to ensure there won't be cycles during resolution).

Parameters:
superType - Abstract type to resolve
subType - Sub-class of superType, to map superTo to
Returns:
This resolver, to allow chaining of initializations

findTypeMapping

public JavaType findTypeMapping(DeserializationConfig config,
                                JavaType type)
Description copied from class: AbstractTypeResolver
Try to locate a subtype for given abstract type, to either resolve to a concrete type, or at least to a more-specific (and hopefully supported) abstract type, one which may have registered deserializers. Method is called before trying to locate registered deserializers (as well as standard abstract type defaulting that core Jackson does), so it is typically implemented to add custom mappings of common abstract types (like specify which concrete implementation to use for binding Lists).

Note that this method does not necessarily have to do full resolution of bindings; that is, it is legal to return type that could be further resolved: caller is expected to keep calling this method on registered resolvers, until a concrete type is located.

Overrides:
findTypeMapping in class AbstractTypeResolver
Parameters:
config - Configuration in use; should always be of type DeserializationConfig

resolveAbstractType

public JavaType resolveAbstractType(DeserializationConfig config,
                                    JavaType type)
Description copied from class: AbstractTypeResolver
Method called to try to resolve an abstract type into concrete type (usually for purposes of deserializing), when no concrete implementation was found. It will be called after checking all other possibilities, including defaulting.

Overrides:
resolveAbstractType in class AbstractTypeResolver
Parameters:
config - Configuration in use; should always be of type DeserializationConfig
type - Type for which materialization maybe needed
Returns:
Resolved concrete type (which should retain generic type parameters of input type, if any), if resolution succeeds; null if resolver does not know how to resolve type