public Class StringDeserializer

Implements abstract tools.jackson.databind.ValueDeserializer.deserialize.

Doc from tools.jackson.databind.ValueDeserializer.deserialize.

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",
          ...
      }
  

       if (p.currentToken() == JsonToken.START_OBJECT) {
         p.nextToken();
       }
  

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)
: Note that this method is never called for the JSON null literal to avoid every deserializer from having to handle null values. Instead, the ValueDeserializer#getNullValue(DeserializationContext) method is called to produce a null value. To influence null handling, custom deserializers should override ValueDeserializer#getNullValue(DeserializationContext) and usually also ValueDeserializer#getNullAccessPattern().

Annotations

@Override

Overrides tools.jackson.databind.deser.std.StdScalarDeserializer.deserializeWithType.

Doc from tools.jackson.databind.deser.std.StdDeserializer.deserializeWithType.

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.

Annotations

@Override

Overrides tools.jackson.databind.ValueDeserializer.getEmptyValue.

Doc from tools.jackson.databind.ValueDeserializer.getEmptyValue.

Method called to determine value to be used for "empty" values (most commonly when deserializing from empty JSON Strings). Usually this is same as getNullValue (which in turn is usually simply Java null), but it can be overridden for specific types. Or, if type should never be converted from empty String, method can also throw an exception.

This method may be called once, or multiple times, depending on what getEmptyAccessPattern() returns.

Default implementation simply calls getNullValue and returns value.

Annotations

@Override

Overrides tools.jackson.databind.ValueDeserializer.getNullValue.

Implements tools.jackson.databind.deser.NullValueProvider.getNullValue.

Doc from tools.jackson.databind.ValueDeserializer.getNullValue.

Method that can be called to determine value to be used for representing null values (values deserialized when JSON token is JsonToken#VALUE_NULL). Usually this is simply Java null, but for some types (especially primitives) it may be necessary to use non-null values.

This method may be called once, or multiple times, depending on what getNullAccessPattern() returns.

Default implementation simply returns null.

Annotations

@Override

Overrides tools.jackson.databind.ValueDeserializer.isCachable.

Doc from tools.jackson.databind.ValueDeserializer.isCachable.

Method called to see if deserializer instance is cachable and usable for other properties of same type (type for which instance was created).

Note that cached instances are still contextualized on per-property basis (but note that ValueDeserializer#resolve(DeserializationContext)d just once!) This means that in most cases it is safe to cache instances; however, it only makes sense to cache instances if instantiation is expensive, or if instances are heavy-weight.

Default implementation returns false, to indicate that no caching is done.

Annotations

@Override

Overrides tools.jackson.databind.deser.std.StdScalarDeserializer.logicalType.

Doc from tools.jackson.databind.ValueDeserializer.logicalType.

Method for accessing logical type of values this deserializer produces. Typically used for further configuring handling of values, for example, to find which coercions are legal.

Annotations

@Override