Jackson 3.0.0-rc3

(another minor update)

Continuing quick pace of pre-release versions, Jackson 3.0.0-rc3 is out now, about 2 weeks after 3.0.0-rc2.

Highlights include:

• Finally fixed Gradle dependencies, metadata (I think!)
• Native JPMS support for 3 more modules — jackson-module-kotlin, jackson-datatype-javax-money, jackson-datatype-moneta — leaving jackson-module-scala as the one and only 3.x Jackson module without JPMS from module-info.java (and based on what I have read, it will remain so)
• Embedding formerly separate Java 8 Date/Time module (jackson-datatype-jsr310) into jackson-databind, similar to 2 previously merged Java 8 modules ( jackson-datatype-jdk8, jackson-module-parameter-names).

all of which were planned as things to include next. One other expected feature — “Replace core Reflection use with MethodHandles” — https://github.com/FasterXML/jackson-databind/pull/5046 — was initially merged but had to be reverted due to problems with datatype modules.
It will likely be included in 3.0.0-rc4.

No More jackson-datatype-jsr310 as separate module

Of this these, the inclusion of Java 8 Date/Time module is probably the most significant change: you no longer have to (or can) register this module — support for java.time types is built in jackson-databind.

Date/Time configuration unification: new DateTimeFeature

After embedding jackson-datatype-jsr310 , a follow-up change was made to create new DateTimeFeature to combine formerly separate configuration features from:

• JavaTimeFeature of Java 8 Date/Time module
• Date/time related DeserializationFeature s (see databind#5067)
• Date/time related SerializationFeature s (see databind#5066)

So now all basic on/off configuration for Date/Time value reading/writing will be configured using DateTimeFeature :

// Can configure Mapper default settings
ObjectMapper mapper = JsonMapper.builder()
   .enable(DateTimeFeature.WRITE_DATES_AS_TIMESTAMPS)
   .build();
// as well as per-call settings via ObjectReader/ObjectWriter
String json = mapper.writer()
   .with(DateTimeFeature.WRITE_DATES_WITH_CONTEXT_TIME_ZONE)
   .writeValueAsString(LocalDateTime.now());

Enum read/write unification: fold into existing EnumFeature

Similar to changes wrt DateTimeFeature, another refactoring was done for Enum configuration. EnumFeature was added back in Jackson 2.14, but there were existing DeserializationFeatures / SerializationFeatures that cannot be moved in Jackson 2.x due to backwards-compatibility constraints.

For 3.0:

• Enum-related DeserializationFeatures (see databind#5079)
• Enum-related SerializationFeatures (see databind#5080)

were folded into EnumFeature so similarly all simple Enum reading/writing configuration will now use this separate configuration feature set:

// Can configure Mapper default settings
ObjectMapper mapper = JsonMapper.builder()
   .enable(EnumFeature.WRITE_ENUMS_USING_TO_STRING)
   .build();
// as well as per-call settings via ObjectReader/ObjectWriter
String json = mapper.writer()
   .with(EnumFeature.WRITE_ENUMS_TO_LOWERCASE)
   .writeValueAsString(MyEnum.FIRST);

Next Steps?

So the next thing will be 3.0.0-rc4 — planning for which is on-going.