Add Jackson 3 support as org.msgpack.jackson3:jackson-dataformat-msgpack

.github/workflows/CI.yml

@@ -28,6 +28,7 @@ jobs:
               - 'project/build.properties'
               - 'msgpack-core/**'
               - 'msgpack-jackson/**'
+              - 'msgpack-jackson3/**'
             docs:
               - '**.md'
               - '**.txt'
@@ -81,8 +82,20 @@ jobs:
       - name: Test
         env:
           TEST_JAVA_HOME: ${{ steps.target-jdk.outputs.path }}
-        run: ./sbt test
+        run: |
+          # msgpack-jackson3 (Jackson 3) requires JDK 17+; older lanes test the
+          # Java 8 compatible modules only
+          if [[ ${{ matrix.java }} -lt 17 ]]; then
+            ./sbt msgpack-core/test msgpack-jackson/test
+          else
+            ./sbt test
+          fi
       - name: Universal Buffer Test
         env:
           TEST_JAVA_HOME: ${{ steps.target-jdk.outputs.path }}
-        run: ./sbt test -J-Dmsgpack.universal-buffer=true
+        run: |
+          if [[ ${{ matrix.java }} -lt 17 ]]; then
+            ./sbt msgpack-core/test msgpack-jackson/test -J-Dmsgpack.universal-buffer=true
+          else
+            ./sbt test -J-Dmsgpack.universal-buffer=true
+          fi

.github/workflows/release.yml

@@ -38,7 +38,17 @@ jobs:
           PGP_PASSPHRASE: ${{ secrets.PGP_PASSPHRASE }}
           TEST_JAVA_HOME: ${{ steps.jdk8.outputs.path }}
         run: |
-          ./sbt publishSigned
+          ./sbt msgpack-core/publishSigned msgpack-jackson/publishSigned
+      # msgpack-jackson3 (Jackson 3) requires JDK 17+
+      - uses: actions/setup-java@v5
+        with:
+          java-version: 17
+          distribution: temurin
+      - name: Build bundle for msgpack-jackson3 (Jackson 3)
+        env:
+          PGP_PASSPHRASE: ${{ secrets.PGP_PASSPHRASE }}
+        run: |
+          ./sbt msgpack-jackson3/publishSigned
       - name: Release to Sonatype
         env:
           SONATYPE_USERNAME: '${{ secrets.SONATYPE_USERNAME }}'

CLAUDE.md

@@ -6,7 +6,8 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 MessagePack-Java is a binary serialization library that provides a fast and compact alternative to JSON. The project consists of two main modules:
 - **msgpack-core**: Standalone MessagePack implementation with no external dependencies
-- **msgpack-jackson**: Jackson integration for object mapping capabilities
+- **msgpack-jackson**: Jackson 2.x integration in maintenance mode (`org.msgpack:jackson-dataformat-msgpack`, Java 8+)
+- **msgpack-jackson3**: Jackson 3.x integration for object mapping capabilities (`org.msgpack.jackson3:jackson-dataformat-msgpack`, Java 17+)
 
 ## Essential Development Commands
 
@@ -49,7 +50,8 @@ The main entry point is the `MessagePack` factory class which creates:
 
 Key locations:
 - Core interfaces: `msgpack-core/src/main/java/org/msgpack/core/`
-- Jackson integration: `msgpack-jackson/src/main/java/org/msgpack/jackson/dataformat/`
+- Jackson 2 integration: `msgpack-jackson/src/main/java/org/msgpack/jackson/dataformat/`
+- Jackson 3 integration: `msgpack-jackson3/src/main/java/org/msgpack/jackson3/dataformat/`
 
 ### Buffer Management System
 MessagePack uses an efficient buffer abstraction layer:
@@ -68,8 +70,8 @@ The msgpack-jackson module provides:
 ### Testing Structure
 - **msgpack-core tests**: Written in Scala (always use the latest Scala 3 version) using AirSpec framework
   - Location: `msgpack-core/src/test/scala/`
-- **msgpack-jackson tests**: Written in Java using JUnit
-  - Location: `msgpack-jackson/src/test/java/`
+- **msgpack-jackson / msgpack-jackson3 tests**: Written in Java using JUnit
+  - Location: `msgpack-jackson/src/test/java/`, `msgpack-jackson3/src/test/java/`
 
 ## Important JVM Options
 

README.md

@@ -53,8 +53,16 @@ For using DirectByteBuffer (off-heap memory access methods) in JDK17, you need t
 
 ### Integration with Jackson ObjectMapper (jackson-databind)
 
-msgpack-java supports serialization and deserialization of Java objects through [jackson-databind](https://github.com/FasterXML/jackson-databind).
-For details, see [msgpack-jackson/README.md](https://github.com/msgpack/msgpack-java/blob/develop/msgpack-jackson/README.md). The template-based serialization mechanism used in v06 is deprecated.
+msgpack-java supports serialization and deserialization of Java objects through [jackson-databind](https://github.com/FasterXML/jackson-databind). The template-based serialization mechanism used in v06 is deprecated.
+
+Two artifacts are published depending on which Jackson major version your project uses:
+
+| Jackson version | groupId | artifactId | Java package | Requirements |
+| --- | --- | --- | --- | --- |
+| Jackson 3.x | `org.msgpack.jackson3` | [`jackson-dataformat-msgpack`](https://github.com/msgpack/msgpack-java/blob/main/msgpack-jackson3/README.md) | `org.msgpack.jackson3.dataformat` | Java 17+ |
+| Jackson 2.x | `org.msgpack` | [`jackson-dataformat-msgpack`](https://github.com/msgpack/msgpack-java/blob/main/msgpack-jackson/README.md) (maintenance mode) | `org.msgpack.jackson.dataformat` | Java 8+ |
+
+The Jackson 2.x artifact keeps the same Maven coordinates and Java package as before, so existing users need no changes. The Jackson 3.x support is published under a new groupId (`org.msgpack.jackson3`) with a new Java package, following the same convention as Jackson itself (`com.fasterxml.jackson.dataformat` → `tools.jackson.dataformat`); renaming the Maven coordinates and the Java package together allows both artifacts to coexist on the same classpath for incremental migration. See each module's README for install instructions and usage details.
 
 - [Release Notes](https://github.com/msgpack/msgpack-java/blob/develop/RELEASE_NOTES.md)
 
@@ -145,5 +153,6 @@ If some sporadic error happens (e.g., Sonatype timeout), rerun `sonaRelease` aga
 
 ```
 msgpack-core                 # Contains packer/unpacker implementation that never uses third-party libraries
-msgpack-jackson              # Contains jackson-dataformat-java implementation
+msgpack-jackson              # org.msgpack:jackson-dataformat-msgpack: Jackson 2.x integration (maintenance mode)
+msgpack-jackson3             # org.msgpack.jackson3:jackson-dataformat-msgpack: Jackson 3.x integration (Java 17+)
 ```

build.sbt

@@ -115,10 +115,22 @@ val buildSettings = Seq[Setting[?]](
   Test / compile    := Def.uncached((Test / compile).dependsOn(Test / jcheckStyle).value)
 )
 
-val junitJupiter = "org.junit.jupiter" % "junit-jupiter"        % "5.14.4" % "test"
-val junitVintage = "org.junit.vintage" % "junit-vintage-engine" % "5.14.4" % "test"
+val junitJupiter   = "org.junit.jupiter" % "junit-jupiter"        % "5.14.4" % "test"
+val junitVintage   = "org.junit.vintage" % "junit-vintage-engine" % "5.14.4" % "test"
+val junitInterface = "com.github.sbt"    % "junit-interface"      % "0.13.3" % "test"
 
 // Project settings
+val isJava17Plus: Boolean = {
+  val v = sys.props.getOrElse("java.specification.version", "1.8")
+  // getOrElse(false): non-numeric versions (e.g. early-access "17-ea") fail safe
+  // by not compiling the Jackson 3 module (msgpack-jackson) rather than making an
+  // optimistic guess.
+  if (v.startsWith("1."))
+    false
+  else
+    scala.util.Try(v.toInt >= 17).getOrElse(false)
+}
+
 lazy val root = Project(id = "msgpack-java", base = file("."))
   .settings(
     buildSettings,
@@ -127,7 +139,14 @@ lazy val root = Project(id = "msgpack-java", base = file("."))
     publish         := {},
     publishLocal    := {}
   )
-  .aggregate(msgpackCore, msgpackJackson)
+  .aggregate(
+    Seq[ProjectReference](msgpackCore, msgpackJackson) ++ (
+      if (isJava17Plus)
+        Seq[ProjectReference](msgpackJackson3)
+      else
+        Nil
+    ): _*
+  )
 
 lazy val msgpackCore = Project(id = "msgpack-core", base = file("msgpack-core"))
   .enablePlugins(SbtOsgi)
@@ -170,21 +189,56 @@ lazy val msgpackCore = Project(id = "msgpack-core", base = file("msgpack-core"))
       )
   )
 
+// Jackson 2.x module. Keeps the same Maven coordinates (org.msgpack:jackson-dataformat-msgpack)
+// and Java package as the 0.9.x line, so existing Jackson 2.x users need no changes.
+// Maintenance mode: Jackson 2.x dependency bumps and bug fixes only.
 lazy val msgpackJackson = Project(id = "msgpack-jackson", base = file("msgpack-jackson"))
   .enablePlugins(SbtOsgi)
   .settings(
     buildSettings,
     name                        := "jackson-dataformat-msgpack",
-    description                 := "Jackson extension that adds support for MessagePack",
+    description                 := "Jackson 2.x extension that adds support for MessagePack",
     OsgiKeys.bundleSymbolicName := "org.msgpack.msgpack-jackson",
     OsgiKeys.exportPackage      := Seq("org.msgpack.jackson", "org.msgpack.jackson.dataformat"),
     libraryDependencies ++=
       Seq(
         "com.fasterxml.jackson.core" % "jackson-databind" % "2.22.1",
         junitJupiter,
         junitVintage,
-        "org.apache.commons" % "commons-math3" % "3.6.1" % "test"
+        "com.github.sbt.junit" % "jupiter-interface" % JupiterKeys.jupiterVersion.value % "test",
+        "org.apache.commons"   % "commons-math3"     % "3.6.1"                          % "test"
       ),
     testOptions += Tests.Argument(TestFrameworks.JUnit, "-v")
   )
   .dependsOn(msgpackCore)
+
+// Jackson 3.x module. Published under a new groupId (org.msgpack.jackson3) with a new
+// Java package (org.msgpack.jackson3.dataformat), following JLBP-6: the Maven coordinates
+// and the Java package are renamed together, so this artifact can coexist on the same
+// classpath with the Jackson 2.x artifact (org.msgpack:jackson-dataformat-msgpack).
+lazy val msgpackJackson3 = Project(id = "msgpack-jackson3", base = file("msgpack-jackson3"))
+  .enablePlugins(SbtOsgi, JmhPlugin)
+  .settings(
+    buildSettings,
+    organization := "org.msgpack.jackson3",
+    name         := "jackson-dataformat-msgpack",
+    // sbt derives build output paths from moduleName, which would collide with the
+    // Jackson 2 module publishing the same artifactId; use the project id instead
+    outputPath                  := s"${platform.value}/u/msgpack-jackson3",
+    description                 := "Jackson 3.x extension that adds support for MessagePack",
+    OsgiKeys.bundleSymbolicName := "org.msgpack.jackson3.jackson-dataformat-msgpack",
+    OsgiKeys.exportPackage      := Seq("org.msgpack.jackson3", "org.msgpack.jackson3.dataformat"),
+    OsgiKeys.importPackage      := Seq("!android.os", "!sun.*"),
+    Test / fork                 := true,
+    javacOptions                := Seq("--release", "17"),
+    doc / javacOptions          := Seq("--release", "17", "-Xdoclint:none"),
+    libraryDependencies ++=
+      Seq("tools.jackson.core" % "jackson-databind" % "3.1.2", junitInterface),
+    testOptions += Tests.Argument(TestFrameworks.JUnit, "-v"),
+    Jmh / javaOptions ++=
+      Seq(
+        "--add-opens=java.base/java.nio=ALL-UNNAMED",
+        "--add-opens=java.base/sun.nio.ch=ALL-UNNAMED"
+      )
+  )
+  .dependsOn(msgpackCore)

msgpack-jackson/README.md

@@ -3,7 +3,9 @@
 [![Maven Central](https://maven-badges.herokuapp.com/maven-central/org.msgpack/jackson-dataformat-msgpack/badge.svg)](https://maven-badges.herokuapp.com/maven-central/org.msgpack/jackson-dataformat-msgpack/)
 [![Javadoc](https://www.javadoc.io/badge/org.msgpack/jackson-dataformat-msgpack.svg)](https://www.javadoc.io/doc/org.msgpack/jackson-dataformat-msgpack)
 
-This Jackson extension library is a component to easily read and write [MessagePack](http://msgpack.org/) encoded data through jackson-databind API.
+This Jackson 2.x extension library is a component to easily read and write [MessagePack](http://msgpack.org/) encoded data through jackson-databind API.
+
+**Maintenance mode:** this module keeps the same Maven coordinates (`org.msgpack:jackson-dataformat-msgpack`) and Java package (`org.msgpack.jackson.dataformat`) as before, so existing Jackson 2.x users need no changes. It receives Jackson 2.x dependency bumps and bug fixes only. For Jackson 3.x, use [`org.msgpack.jackson3:jackson-dataformat-msgpack`](../msgpack-jackson3/) (Java 17+), which uses a different groupId and Java package so both artifacts can coexist on the same classpath.
 
 It extends standard Jackson streaming API (`JsonFactory`, `JsonParser`, `JsonGenerator`), and as such works seamlessly with all the higher level data abstractions (data binding, tree model, and pluggable extensions). For the details of Jackson-annotations, please see https://github.com/FasterXML/jackson-annotations.
 

msgpack-jackson/src/main/java/org/msgpack/jackson/dataformat/MessagePackParser.java

@@ -585,13 +585,14 @@ public JsonStreamContext getParsingContext()
     @Override
     public JsonLocation currentTokenLocation()
     {
-        return new JsonLocation(ioContext.contentReference(), tokenPosition, -1, -1);
+        // Byte offset is exposed as columnNr since JsonLocation has no field for it
+        return new JsonLocation(ioContext.contentReference(), tokenPosition, -1, -1, (int) tokenPosition);
     }
 
     @Override
     public JsonLocation currentLocation()
     {
-        return new JsonLocation(ioContext.contentReference(), currentPosition, -1, -1);
+        return new JsonLocation(ioContext.contentReference(), currentPosition, -1, -1, (int) currentPosition);
     }
 
     @Override

msgpack-jackson/src/test/java/org/msgpack/jackson/dataformat/MessagePackDataformatTestBase.java

@@ -19,8 +19,8 @@
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import org.junit.After;
-import org.junit.Before;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
@@ -49,7 +49,7 @@ public class MessagePackDataformatTestBase
     protected TinyPojo tinyPojo;
     protected ComplexPojo complexPojo;
 
-    @Before
+    @BeforeEach
     public void setup()
     {
         factory = new MessagePackFactory();
@@ -100,7 +100,7 @@ public void setup()
         complexPojo.values = Arrays.asList("one", "two", "three");
     }
 
-    @After
+    @AfterEach
     public void teardown()
     {
         if (in != null) {