UntypedObjectDeserializer doesn't look
for native type information when handling scalar values, but Avro sometimes includes type information in the schema for scalar values;
This subclass checks for the presence of valid type information and calls out to the type deserializer even for scalar values. The
same goes for map keys.
| Modifier and Type | Field and Description |
|---|---|
| protected TypeDeserializer |
| Access | Constructor and Description |
|---|---|
| public |
| Modifier and Type | Method and Description |
|---|---|
| public static AvroUntypedDeserializer | |
| public Object | deserialize(JsonParser p, DeserializationContext ctxt)
Overrides tools. Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles. |
| public Object | deserializeWithType(JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer)
Overrides tools. Base implementation that does not assume specific type inclusion mechanism. |
| protected Object | mapObject(JsonParser p, DeserializationContext ctxt)
Overrides tools. Method called to map a JSON Object into a Java value. |
| public void | resolve(DeserializationContext ctxt)
Overrides tools. We need to implement this method to properly find things to delegate to: it cannot be done earlier since delegated deserializers almost certainly require access to this instance (at least "List" and "Map" ones) |
| _typeDeserializer | back to summary |
|---|---|
| protected TypeDeserializer _typeDeserializer | |
| AvroUntypedDeserializer | back to summary |
|---|---|
| public AvroUntypedDeserializer(JavaType listType, JavaType mapType) | |
| construct | back to summary |
|---|---|
| public static AvroUntypedDeserializer construct(TypeFactory f) | |
| deserialize | back to summary |
|---|---|
| public Object deserialize(JsonParser p, DeserializationContext ctxt) throws JacksonException Overrides tools. Doc from tools. Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles. Returned instance is to be constructed by method itself. Pre-condition for this method is that the parser points to the first event that is part of value to deserializer (and which is never JSON 'null' literal, more on this below): for simple types it may be the only value; and for structured types the Object start marker or a FIELD_NAME. The two possible input conditions for structured types result from polymorphism via fields. In the ordinary case, Jackson calls this method when it has encountered an OBJECT_START, and the method implementation must advance to the next token to see the first field name. If the application configures polymorphism via a field, then the object looks like the following.
{
"@class": "class name",
...
}
Jackson consumes the two tokens (the @class field name
and its value) in order to learn the class and select the deserializer.
Thus, the stream is pointing to the FIELD_NAME for the first field
after the @class. Thus, if you want your method to work correctly
both with and without polymorphism, you must begin your method with:
if (p.currentToken() == JsonToken.START_OBJECT) {
p.nextToken();
}
This results in the stream pointing to the field name, so that
the two conditions align.
Post-condition is that the parser will point to the last event that is part of deserialized value (or in case deserialization fails, event that was not recognized or usable, which may be the same event as the one it pointed to upon call).
Handling null values (JsonToken.VALUE_NULL)
| |
| deserializeWithType | back to summary |
|---|---|
| public Object deserializeWithType(JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer) throws JacksonException Overrides tools. Doc from tools. Base implementation that does not assume specific type inclusion mechanism. Sub-classes are expected to override this method if they are to handle type information.
| |
| mapObject | back to summary |
|---|---|
| protected Object mapObject(JsonParser p, DeserializationContext ctxt) throws JacksonException Overrides tools. Method called to map a JSON Object into a Java value.
| |
| resolve | back to summary |
|---|---|
| public void resolve(DeserializationContext ctxt) Overrides tools. Doc from tools. We need to implement this method to properly find things to delegate to: it cannot be done earlier since delegated deserializers almost certainly require access to this instance (at least "List" and "Map" ones)
| |