org.codehaus.jackson.map.deser
Class StdDeserializerProvider

java.lang.Object
  extended by org.codehaus.jackson.map.DeserializerProvider
      extended by org.codehaus.jackson.map.deser.StdDeserializerProvider

public class StdDeserializerProvider
extends DeserializerProvider

Default DeserializerProvider implementation. Handles low-level caching (non-root) aspects of deserializer handling; all construction details are delegated to configured DeserializerFactory instance that the provider owns.


Field Summary
protected  ConcurrentHashMap<JavaType,JsonDeserializer<Object>> _cachedDeserializers
          We will also cache some dynamically constructed deserializers; specifically, ones that are expensive to construct.
 
Constructor Summary
StdDeserializerProvider()
          Default constructor.
StdDeserializerProvider(DeserializerFactory f)
           
 
Method Summary
protected  JsonDeserializer<Object> _createAndCacheValueDeserializer(DeserializationConfig config, JavaType type, JavaType referrer, String refPropName)
          Method that will try to create a deserializer for given type, and resolve and cache it if necessary
protected  JsonDeserializer<Object> _createDeserializer(DeserializationConfig config, JavaType type, JavaType referrer, String refPropName)
           
protected  JsonDeserializer<Object> _findCachedDeserializer(JavaType type)
           
protected  KeyDeserializer _handleUnknownKeyDeserializer(JavaType type)
           
protected  JsonDeserializer<Object> _handleUnknownValueDeserializer(JavaType type)
           
protected  void _resolveDeserializer(DeserializationConfig config, ResolvableDeserializer ser)
           
 int cachedDeserializersCount()
          Method that can be used to determine how many deserializers this provider is caching currently (if it does caching: default implementation does) Exact count depends on what kind of deserializers get cached; default implementation caches only dynamically constructed deserializers, but not eagerly constructed standard deserializers (which is different from how serializer provider works).
 KeyDeserializer findKeyDeserializer(DeserializationConfig config, JavaType type)
          Method called to get hold of a deserializer to use for deserializing keys for Map.
 JsonDeserializer<Object> findValueDeserializer(DeserializationConfig config, JavaType type, JavaType referrer, String refPropName)
          Method called to get hold of a deserializer for a value of given type; or if no such deserializer can be found, a default handler (which may do a best-effort generic serialization or just simply throw an exception when invoked).
 void flushCachedDeserializers()
          Method that will drop all dynamically constructed deserializers (ones that are counted as result value for cachedDeserializersCount()).
 boolean hasValueDeserializerFor(DeserializationConfig config, JavaType type)
          Method that can be called to find out whether a deserializer can be found for given type
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

_cachedDeserializers

protected final ConcurrentHashMap<JavaType,JsonDeserializer<Object>> _cachedDeserializers
We will also cache some dynamically constructed deserializers; specifically, ones that are expensive to construct. This currently means bean and Enum deserializers; array, List and Map deserializers will not be cached.

Given that we don't expect much concurrency for additions (should very quickly converge to zero after startup), let's explicitly define a low concurrency setting.

Constructor Detail

StdDeserializerProvider

public StdDeserializerProvider()
Default constructor. Equivalent to calling
   new StdDeserializerProvider(BeanDeserializerFactory.instance);


StdDeserializerProvider

public StdDeserializerProvider(DeserializerFactory f)
Method Detail

findValueDeserializer

public JsonDeserializer<Object> findValueDeserializer(DeserializationConfig config,
                                                      JavaType type,
                                                      JavaType referrer,
                                                      String refPropName)
                                               throws JsonMappingException
Description copied from class: DeserializerProvider
Method called to get hold of a deserializer for a value of given type; or if no such deserializer can be found, a default handler (which may do a best-effort generic serialization or just simply throw an exception when invoked).

Note: this method is only called for value types; not for keys. Key deserializers can be accessed using DeserializerProvider.findKeyDeserializer(org.codehaus.jackson.map.DeserializationConfig, org.codehaus.jackson.type.JavaType).

Specified by:
findValueDeserializer in class DeserializerProvider
type - Declared type of the value to deserializer (obtained using 'setter' method signature and/or type annotations
referrer - Type that contains the value, if any: null for root-level object.
refPropName - Logical name of the property within instance of referrer, if through a property (field). Null for Collection and Array types, where reference is not through a field, as well as for "any property" fallback references
Throws:
JsonMappingException - if there are fatal problems with accessing suitable deserializer; including that of not finding any serializer

findKeyDeserializer

public KeyDeserializer findKeyDeserializer(DeserializationConfig config,
                                           JavaType type)
                                    throws JsonMappingException
Description copied from class: DeserializerProvider
Method called to get hold of a deserializer to use for deserializing keys for Map.

Specified by:
findKeyDeserializer in class DeserializerProvider
Throws:
JsonMappingException - if there are fatal problems with accessing suitable key deserializer; including that of not finding any serializer

hasValueDeserializerFor

public boolean hasValueDeserializerFor(DeserializationConfig config,
                                       JavaType type)
Method that can be called to find out whether a deserializer can be found for given type

Specified by:
hasValueDeserializerFor in class DeserializerProvider

cachedDeserializersCount

public int cachedDeserializersCount()
Description copied from class: DeserializerProvider
Method that can be used to determine how many deserializers this provider is caching currently (if it does caching: default implementation does) Exact count depends on what kind of deserializers get cached; default implementation caches only dynamically constructed deserializers, but not eagerly constructed standard deserializers (which is different from how serializer provider works).

The main use case for this method is to allow conditional flushing of deserializer cache, if certain number of entries is reached.

Specified by:
cachedDeserializersCount in class DeserializerProvider

flushCachedDeserializers

public void flushCachedDeserializers()
Method that will drop all dynamically constructed deserializers (ones that are counted as result value for cachedDeserializersCount()). This can be used to remove memory usage (in case some deserializers are only used once or so), or to force re-construction of deserializers after configuration changes for mapper than owns the provider.

Specified by:
flushCachedDeserializers in class DeserializerProvider
Since:
1.4

_findCachedDeserializer

protected JsonDeserializer<Object> _findCachedDeserializer(JavaType type)

_createAndCacheValueDeserializer

protected JsonDeserializer<Object> _createAndCacheValueDeserializer(DeserializationConfig config,
                                                                    JavaType type,
                                                                    JavaType referrer,
                                                                    String refPropName)
                                                             throws JsonMappingException
Method that will try to create a deserializer for given type, and resolve and cache it if necessary

Throws:
JsonMappingException

_createDeserializer

protected JsonDeserializer<Object> _createDeserializer(DeserializationConfig config,
                                                       JavaType type,
                                                       JavaType referrer,
                                                       String refPropName)
                                                throws JsonMappingException
Throws:
JsonMappingException

_resolveDeserializer

protected void _resolveDeserializer(DeserializationConfig config,
                                    ResolvableDeserializer ser)
                             throws JsonMappingException
Throws:
JsonMappingException

_handleUnknownValueDeserializer

protected JsonDeserializer<Object> _handleUnknownValueDeserializer(JavaType type)
                                                            throws JsonMappingException
Throws:
JsonMappingException

_handleUnknownKeyDeserializer

protected KeyDeserializer _handleUnknownKeyDeserializer(JavaType type)
                                                 throws JsonMappingException
Throws:
JsonMappingException