public final class DeserializerCache extends Object implements Serializable
ObjectMapper
,
DeserializationContext
)
and classes that construct deserializers
(DeserializerFactory
).Modifier and Type | Field and Description |
---|---|
protected ConcurrentHashMap<JavaType,JsonDeserializer<Object>> |
_cachedDeserializers
We will also cache some dynamically constructed deserializers;
specifically, ones that are expensive to construct.
|
protected HashMap<JavaType,JsonDeserializer<Object>> |
_incompleteDeserializers
During deserializer construction process we may need to keep track of partially
completed deserializers, to resolve cyclic dependencies.
|
Constructor and Description |
---|
DeserializerCache() |
Modifier and Type | Method and Description |
---|---|
protected JsonDeserializer<Object> |
_createAndCache2(DeserializationContext ctxt,
DeserializerFactory factory,
JavaType type)
Method that handles actual construction (via factory) and caching (both
intermediate and eventual)
|
protected JsonDeserializer<Object> |
_createAndCacheValueDeserializer(DeserializationContext ctxt,
DeserializerFactory factory,
JavaType type)
Method that will try to create a deserializer for given type,
and resolve and cache it if necessary
|
protected JsonDeserializer<Object> |
_createDeserializer(DeserializationContext ctxt,
DeserializerFactory factory,
JavaType type)
Method that does the heavy lifting of checking for per-type annotations,
find out full type, and figure out which actual factory method
to call.
|
protected JsonDeserializer<?> |
_createDeserializer2(DeserializationContext ctxt,
DeserializerFactory factory,
JavaType type,
BeanDescription beanDesc) |
protected JsonDeserializer<Object> |
_findCachedDeserializer(JavaType type) |
protected KeyDeserializer |
_handleUnknownKeyDeserializer(JavaType type) |
protected JsonDeserializer<Object> |
_handleUnknownValueDeserializer(JavaType type) |
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).
|
protected Converter<Object,Object> |
findConverter(DeserializationContext ctxt,
Annotated a) |
protected JsonDeserializer<Object> |
findConvertingDeserializer(DeserializationContext ctxt,
Annotated a,
JsonDeserializer<Object> deser)
Helper method that will check whether given annotated entity (usually class,
but may also be a property accessor) indicates that a
Converter is to
be used; and if so, to construct and return suitable serializer for it. |
protected JsonDeserializer<Object> |
findDeserializerFromAnnotation(DeserializationContext ctxt,
Annotated ann)
Helper method called to check if a class or method
has annotation that tells which class to use for deserialization.
|
KeyDeserializer |
findKeyDeserializer(DeserializationContext ctxt,
DeserializerFactory factory,
JavaType type)
Method called to get hold of a deserializer to use for deserializing
keys for
Map . |
JsonDeserializer<Object> |
findValueDeserializer(DeserializationContext ctxt,
DeserializerFactory factory,
JavaType propertyType)
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(DeserializationContext ctxt,
DeserializerFactory factory,
JavaType type)
Method called to find out whether provider would be able to find
a deserializer for given type, using a root reference (i.e.
|
protected final ConcurrentHashMap<JavaType,JsonDeserializer<Object>> _cachedDeserializers
Given that we don't expect much concurrency for additions (should very quickly converge to zero after startup), let's define a relatively low concurrency setting.
protected final HashMap<JavaType,JsonDeserializer<Object>> _incompleteDeserializers
public int cachedDeserializersCount()
The main use case for this method is to allow conditional flushing of deserializer cache, if certain number of entries is reached.
public void flushCachedDeserializers()
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.public JsonDeserializer<Object> findValueDeserializer(DeserializationContext ctxt, DeserializerFactory factory, JavaType propertyType) throws JsonMappingException
Note: this method is only called for value types; not for keys.
Key deserializers can be accessed using findKeyDeserializer(com.fasterxml.jackson.databind.DeserializationContext, com.fasterxml.jackson.databind.deser.DeserializerFactory, com.fasterxml.jackson.databind.JavaType)
.
Note also that deserializer returned is guaranteed to be resolved
(if it is of type ResolvableDeserializer
), but
not contextualized (wrt ContextualDeserializer
): caller
has to handle latter if necessary.
ctxt
- Deserialization contextpropertyType
- Declared type of the value to deserializer (obtained using
'setter' method signature and/or type annotationsJsonMappingException
- if there are fatal problems with
accessing suitable deserializer; including that of not
finding any serializerpublic KeyDeserializer findKeyDeserializer(DeserializationContext ctxt, DeserializerFactory factory, JavaType type) throws JsonMappingException
Map
.JsonMappingException
- if there are fatal problems with
accessing suitable key deserializer; including that of not
finding any serializerpublic boolean hasValueDeserializerFor(DeserializationContext ctxt, DeserializerFactory factory, JavaType type) throws JsonMappingException
JsonMappingException
protected JsonDeserializer<Object> _findCachedDeserializer(JavaType type)
protected JsonDeserializer<Object> _createAndCacheValueDeserializer(DeserializationContext ctxt, DeserializerFactory factory, JavaType type) throws JsonMappingException
ctxt
- Currently active deserialization contexttype
- Type of property to deserializeJsonMappingException
protected JsonDeserializer<Object> _createAndCache2(DeserializationContext ctxt, DeserializerFactory factory, JavaType type) throws JsonMappingException
JsonMappingException
protected JsonDeserializer<Object> _createDeserializer(DeserializationContext ctxt, DeserializerFactory factory, JavaType type) throws JsonMappingException
JsonMappingException
protected JsonDeserializer<?> _createDeserializer2(DeserializationContext ctxt, DeserializerFactory factory, JavaType type, BeanDescription beanDesc) throws JsonMappingException
JsonMappingException
protected JsonDeserializer<Object> findDeserializerFromAnnotation(DeserializationContext ctxt, Annotated ann) throws JsonMappingException
JsonMappingException
protected JsonDeserializer<Object> findConvertingDeserializer(DeserializationContext ctxt, Annotated a, JsonDeserializer<Object> deser) throws JsonMappingException
Converter
is to
be used; and if so, to construct and return suitable serializer for it.
If not, will simply return given serializer as is.JsonMappingException
protected Converter<Object,Object> findConverter(DeserializationContext ctxt, Annotated a) throws JsonMappingException
JsonMappingException
protected JsonDeserializer<Object> _handleUnknownValueDeserializer(JavaType type) throws JsonMappingException
JsonMappingException
protected KeyDeserializer _handleUnknownKeyDeserializer(JavaType type) throws JsonMappingException
JsonMappingException
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