JacksonFeatures

Jackson features

Features configurable via ObjectMapper, ObjectWriter and ObjectReader are divide into two main categories: high-level settings that affect jackson-databind components directly; and low-level settings that affect behavior of Streaming API behavior (JsonParser, JsonGenerator).

Databind features

For core databinding, features are divided further in 3 categories:

• [Mapper features](Mapper Features)
• [Serialization features](Serialization Features) (writing POJOs as JSON and other formats)
• [Deserialization features](Deserialization Features) (reading JSON and other formats as POJOs)

Of these, Mapper Features can only be modified before using ObjectMapper: changes after use may or may not take effects. If you need different configured mapper (or ObjectWriter or ObjectReader), you will need a new mapper instance: you can do this with ObjectMapper.copy() -- it will copy current settings, but allow changes to Mapper Features.

Both Serialization and Deserialization features may, however, be configured by constructing new ObjectReader and ObjectWriter instances like so:

ObjectWriter w = mapper.write(SerializationFeature.WRAP_ROOT_VALUE);
ObjectWriter w2 = w.without(SerializationFeature.WRITE_DURATIONS_AS_TIMESTAMPS);
ObjectReader r = mapper.reader(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS);
ObjectReader r2 = r2.with(DeserializationFeature.USE_JAVA_ARRAY_FOR_JSON_ARRAY)
   .without(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);

Additional notes:

• Most databind features do NOT affect Tree Model (JsonNode) since Tree Model is meant to be 1-to-1 representation of underlying physical content, and as such, minimal amount of converting is done on purpose.

Streaming API features

Similarly, low-level features are divided in 3 categories