public abstract class FromStringDeserializer<T> extends StdScalarDeserializer<T>
String.trim().
Partial deserializer implementation will try to first access current token as
a String, calls _deserialize(String,DeserializationContext) and
returns return value.
If this does not work (current token not a simple scalar type), attempts
are made so that:
JsonToken.VALUE_EMBEDDED_OBJECT) are returned as-is
if they are of compatible type
DeserializationFeature.UNWRAP_SINGLE_VALUE_ARRAYS
is enabled, and array contains just a single scalar value that can be deserialized
(for example, JSON Array with single JSON String element).
Special handling includes:
JsonToken.VALUE_NULL) are handled by returning value
returned by JsonDeserializer.getNullValue(DeserializationContext): default
implementation simply returns Java `null` but this may be overridden.
_deserializeFromEmptyString()
getting called, and return value being returned as deserialization: default implementation
simply returns `null`.
| Modifier and Type | Class and Description |
|---|---|
static class |
FromStringDeserializer.Std
"Chameleon" deserializer that works on simple types that are deserialized
from a simple String.
|
JsonDeserializer.None_valueClass, _valueType, F_MASK_ACCEPT_ARRAYS, F_MASK_INT_COERCIONS| Modifier | Constructor and Description |
|---|---|
protected |
FromStringDeserializer(Class<?> vc) |
| Modifier and Type | Method and Description |
|---|---|
protected abstract T |
_deserialize(String value,
DeserializationContext ctxt) |
protected T |
_deserializeEmbedded(Object ob,
DeserializationContext ctxt) |
protected T |
_deserializeFromEmptyString() |
T |
deserialize(JsonParser p,
DeserializationContext ctxt)
Method that can be called to ask implementation to deserialize
JSON content into the value type this serializer handles.
|
static FromStringDeserializer.Std |
findDeserializer(Class<?> rawType)
Factory method for trying to find a deserializer for one of supported
types that have simple from-String serialization.
|
static Class<?>[] |
types() |
deserialize, deserializeWithType, getEmptyAccessPattern, getNullAccessPattern, supportsUpdate_byteOverflow, _coercedTypeDesc, _coerceEmptyString, _coerceIntegral, _coerceNullToken, _coerceTextualNull, _deserializeFromArray, _deserializeFromEmpty, _deserializeWrappedValue, _failDoubleToIntCoercion, _findNullProvider, _hasTextualNull, _intOverflow, _isEmptyOrTextualNull, _isIntNumber, _isNaN, _isNegInf, _isPosInf, _neitherNull, _nonNullNumber, _parseBooleanFromInt, _parseBooleanPrimitive, _parseBytePrimitive, _parseDate, _parseDate, _parseDateFromArray, _parseDoublePrimitive, _parseDoublePrimitive, _parseFloatPrimitive, _parseFloatPrimitive, _parseIntPrimitive, _parseIntPrimitive, _parseLongPrimitive, _parseLongPrimitive, _parseShortPrimitive, _parseString, _reportFailedNullCoerce, _shortOverflow, _verifyEndArrayForSingle, _verifyNullForPrimitive, _verifyNullForPrimitiveCoercion, _verifyNullForScalarCoercion, _verifyNumberForScalarCoercion, _verifyStringForScalarCoercion, findContentNullProvider, findContentNullStyle, findConvertingContentDeserializer, findDeserializer, findFormatFeature, findFormatOverrides, findValueNullProvider, getValueClass, getValueType, getValueType, handledType, handleMissingEndArrayForSingle, handleUnknownProperty, isDefaultDeserializer, isDefaultKeyDeserializer, parseDoubledeserializeWithType, findBackReference, getDelegatee, getEmptyValue, getEmptyValue, getKnownPropertyNames, getNullValue, getNullValue, getObjectIdReader, isCachable, replaceDelegatee, unwrappingDeserializerprotected FromStringDeserializer(Class<?> vc)
public static Class<?>[] types()
public static FromStringDeserializer.Std findDeserializer(Class<?> rawType)
public T deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
JsonDeserializerPre-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).
Note that this method is never called for JSON null literal, and thus deserializers need (and should) not check for it.
deserialize in class JsonDeserializer<T>p - Parsed used for reading JSON contentctxt - Context that can be used to access information about
this deserialization activity.IOExceptionprotected abstract T _deserialize(String value, DeserializationContext ctxt) throws IOException
IOExceptionprotected T _deserializeEmbedded(Object ob, DeserializationContext ctxt) throws IOException
IOExceptionprotected T _deserializeFromEmptyString() throws IOException
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