Jackson Release 2.18

Jackson Version 2.18 development is planned to start in March, 2024.

This wiki page gives a list of links to all changes (with brief descriptions) that will be included, as well as about original plans for bigger changes (and in some cases changes to plans, postponing).

Status

Branch is waiting to be created.

Patches

No release yet

Documentation

Articles, Blog posts

Changes, compatibility

Compatibility: platform requirements

JDK

Same as Jackson 2.17

Changes, behavior

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Planned major things

Most wanted Features planned

• databind#562: Allow @JsonAnySetter to flow through Creators
  • In-progress, likely to get included
• databind#512: Add @JsonWrapped
  • Matching annotations issue: annotations#42

Functionality improvements planned

• Fix handling of null Type Id with JsonGenerator.writeTypePrefix() (and databind-level TypeIdSerializer)
  • Issue: databind#4407
  • Background:
    • See databind#4354 for immediate problem with null type id
    • See databind#3307 that seems like regression

Performance improvements planned

• More optimized JsonParser.getFloatValue() / JsonParser.getDoubleValue(): avoid String creation when calling FastDoubleParser
  • core#1229: Add char[] versions for NumberInput parseFloat, parseDouble, parseBigInteger
    • implemented; but not used by databind or core itself
  • core#1284: Optimize JsonParser.getDoubleValue()/getFloatValue()/getDecimalValue() to avoid String allocation
    • possible regression for Deferred handling: currently eagerly construct String to ensure most accurate representations (but should instead only do when required)

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Major focus area(s) implemented

The Focus: Rewrite POJO Property Introspection

• [https://github.com/FasterXML/jackson-databind/issues/4515] -- fully rewritten POJO (including Record) Property Introspection
  • Solved 5 previously failing unit tests:
    • (only for 3.0) #538: Injection when there is cyclic references fails
    • #806: Problem with NamingStrategy, creator methods with implicit names
    • #2977: Incompatible FAIL_ON_MISSING_PRIMITIVE_PROPERTIES and field level @JsonProperty
    • #3241: constructorDetector seems to invalidate defaultSetterInfo for nullability
    • #4119: Exception when deserialization uses a record with a constructor property with access=READ_ONLY

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Full Change list

Changes, core

Annotations

Streaming

• #1230: Improve performance of float and double parsing from TextBuffer
• #1251: InternCache - replace synchronized with ReentrantLock
• #1252: ThreadLocalBufferManager replace synchronized with ReentrantLock
• #1257: Increase InternCache default max size from 100 to 200
• #1262: Add diagnostic method pooledCount() in RecyclerPool
• #1264: Rename shaded ch.randelshofer:fastdoubleparser classes to prevent use by downstream consumers
• #1271: Deprecate LockFreePool implementation in 2.18 (remove from 3.0)
• #1277: Add back Java 22 optimisation in FastDoubleParser

Databind

• #806: Problem with NamingStrategy, creator methods with implicit names
• #2977: Incompatible FAIL_ON_MISSING_PRIMITIVE_PROPERTIES and field level @JsonProperty
• #3241: constructorDetector seems to invalidate defaultSetterInfo for nullability
• #4119: Exception when deserialization uses a record with a constructor property with access=READ_ONLY
• #4356: BeanDeserializerModifier::updateBuilder() doesn't work for beans with Creator methods
• #4452: @JsonProperty not serializing field names properly on @JsonCreator in Record
• #4453: Allow JSON Integer to deserialize into a single-arg constructor of parameter type double
• #4456: Rework locking in DeserializerCache
• #4458: Rework synchronized block from BeanDeserializerBase
• #4464: When Include.NON_DEFAULT setting is used, isEmpty() method is not called on the serializer
• #4472: Rework synchronized block in TypeDeserializerBase
• #4483: Remove final on method BeanSerializer.serialize()
• #4515: Rewrite Bean Property Introspection logic in Jackson 2.x
• #4570: Deprecate ObjectMapper.canDeserialize()/ObjectMapper.canSerialize()

Changes, data formats

Avro

• #494: Avro Schema generation: allow mapping Java Enum properties to Avro String values

CSV

• #468: Remove synchronization from CsvMapper
• #469: Allow CSV to differentiate between null and empty fields (foo,,bar vs. foo,"",bar)

Protobuf

• #484: Rework synchronization in ProtobufMapper

Changes, Other modules

JAXB Annotations

• #233: Tolerate JAX-RS 2.2 in jackson-module-jaxb-annotations so that it can be deployed in Liberty alongside features which use 2.2

Changes, JVM Languages

Kotlin

Scala

Changes, Providers

Changes, other

Jackson-jr

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