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Jackson 3.0 Removal of Deprecated 2.x Modules

Author

Tatu Saloranta (@cowtowncoder)

Version history

• 2024-12-01: Created first version

Status

Being discussed; some implementation

Overview

During Jackson 2.x, some Modules have become unnecessary either in general, or for future use. For example:

• jackson-datatype-jdk8 (part of jackson-modules-java8)has been merged into jackson-databind version 3.0.0-SNAPSHOT
  • Functionality now supported directly by jackson-databind so module no longer needed
• jackson-module-parameter-names (part of jackson-modules-java8)has been merged into jackson-databind version 3.0.0-SNAPSHOT
  • Functionality now supported directly by jackson-databind so module no longer needed
• jackson-module-paranamer module (part of jackson-modules-base) was useful before Java 8, but it becomes unnecessary with Java 8 when JDK bytecode can contain parameter names.

Other modules have become unsupported/unmaintained:

• jackson-module-jsonSchema:
  • Has no active maintainer, no one volunteered
  • Only supports older JSON Schema v3 (which is incompatible with newer schema versions, v4 and above)
  • Has become obsolete due to existence of other maintained, external JSON Schema generators (like https://github.com/mbknor/mbknor-jackson-jsonSchema)
• [jackson-datatype-hibernate]
  • Has no active maintainer, no one volunteered
  • Has received some contributions

In these cases, no work has been done to prepare for Jackson 3.0.0 version of the components, and README.mds have been update to indicate a note of Deprecation.

Proposal

The current plan for following Modules:

• jackson-datatype-jdk8
• jackson-module-parameter-names
• jackson-module-paranamer
• jackson-module-schema (and variants)
• jackson-datatype-hibernate5 (and variants)
  • Polls completed, all voted on No -- I do not use these modules

is to

• Keep on publishing 2.x versions (deprecated but maintained)
• Not update repos for 3.0 (master just points to latest 2.x version)
• Not publish 3.0.0-SNAPSHOT, release candidates or actual 3.0.0 version

Above can be changed for specific modules if (and only if):

• There is continued need for module AND
• We can find an active maintainer (in case one is needed; specifically for Hibernate module)