Move to Jackson 3 #2173

pvillard31 · 2025-12-21T15:03:00Z

Description

Following discussion in #2166.
Fixes #2166.

For reference: https://github.com/FasterXML/jackson/blob/main/jackson3/MIGRATING_TO_JACKSON_3.md

These changes are only targeting the 2.x line since it may be considered as containing breaking changes and requires a minimum java version of Java 17.

Before submitting a PR:

Changes must not break binary backwards compatibility. If you are unclear on how to make the change you think is needed while maintaining backward compatibility, CONTRIBUTING.md for details.
Add JavaDocs and other comments explaining the behavior.
When adding or updating methods that fetch entities, add @link JavaDoc entries to the relevant documentation on https://docs.github.com/en/rest .
Add tests that cover any added or changed code. This generally requires capturing snapshot test data. See CONTRIBUTING.md for details.
Run mvn -D enable-ci clean install site "-Dsurefire.argLine=--add-opens java.base/java.net=ALL-UNNAMED" locally. If this command doesn't succeed, your change will not pass CI.
Push your changes to a branch other than main. You will create your PR from that branch.

When creating a PR:

Fill in the "Description" above with clear summary of the changes. This includes:
- If this PR fixes one or more issues, include "Fixes #" lines for each issue.
- Provide links to relevant documentation on https://docs.github.com/en/rest where possible. If not including links, explain why not.
All lines of new code should be covered by tests as reported by code coverage. Any lines that are not covered must have PR comments explaining why they cannot be covered. For example, "Reaching this particular exception is hard and is not a particular common scenario."
Enable "Allow edits from maintainers".

bitwiseman · 2025-12-24T01:53:09Z

pom.xml

+        <type>pom</type>
+        <scope>import</scope>
+      </dependency>
+      <!-- Jackson 3.0 requires jackson-annotations 2.20 -->


https://github.com/FasterXML/jackson/blob/main/jackson3/MIGRATING_TO_JACKSON_3.md

Jackson 3.0 uses jackson-annotations 2.20

bitwiseman · 2025-12-24T01:53:59Z

This is cool. I look forward to you fixing the build errors.

pvillard31 · 2025-12-24T12:43:03Z

Builds are green locally except for

Error: Failed to execute goal com.github.siom79.japicmp:japicmp-maven-plugin:0.23.1:cmp (default) on project github-api: There is at least one incompatibility: org.kohsuke.github.GitHub.getMappingObjectReader():METHOD_RETURN_TYPE_CHANGED,org.kohsuke.github.GitHub.getMappingObjectWriter():METHOD_RETURN_TYPE_CHANGED -> [Help 1]

which I believe is an expected breaking change.

yeikel · 2026-01-14T17:23:16Z

This is cool. I look forward to you fixing the build errors.

Any chance you can review this again?

bitwiseman · 2026-01-23T19:10:30Z

src/main/java/org/kohsuke/github/GHEventInfo.java

     */
    public <T extends GHEventPayload> T getPayload(Class<T> type) throws IOException {
-        T v = GitHubClient.getMappingObjectReader(root()).readValue(payload.traverse(), type);
+        T v = GitHubClient.getMappingObjectReader(root()).forType(type).readValue(payload);


It looks like ForType has been available since 2.5:
https://fasterxml.github.io/jackson-databind/javadoc/2.6/com/fasterxml/jackson/databind/ObjectWriter.html#forType-java.lang.Class-

bitwiseman · 2026-01-23T19:17:48Z

src/test/java/org/kohsuke/github/AotIntegrationTest.java

    private Stream<String> readAotConfigToStreamOfClassNames(String reflectionConfig) throws IOException {
        byte[] reflectionConfigFileAsBytes = Files.readAllBytes(Path.of(reflectionConfig));
-        ArrayNode reflectConfigJsonArray = (ArrayNode) new ObjectMapper().readTree(reflectionConfigFileAsBytes);
+        ArrayNode reflectConfigJsonArray = (ArrayNode) JsonMapper.builder()


JsonMapper has existed since 2.11:
https://fasterxml.github.io/jackson-databind/javadoc/2.11/com/fasterxml/jackson/databind/json/JsonMapper.html

bitwiseman · 2026-01-23T19:23:13Z

src/test/java/org/kohsuke/github/internal/graphql/response/GHGraphQLResponseMockTest.java

-        ObjectMapper objectMapper = new ObjectMapper();
-        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    private GHGraphQLResponse<Object> convertJsonToGraphQLResponse(String json) throws JacksonException {
+        JsonMapper mapper = JsonMapper.builder().disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();


FAIL_ON_UNKNOWN_PROPERTIES has been around since 2.6 or earlier:
https://fasterxml.github.io/jackson-databind/javadoc/2.6/com/fasterxml/jackson/databind/DeserializationFeature.html

bitwiseman · 2026-01-23T19:25:00Z

src/main/java/org/kohsuke/github/GitHubClient.java

-    private static final ObjectMapper MAPPER = new ObjectMapper();
+    private static final JsonMapper MAPPER = JsonMapper.builder()
+            // Use annotations and enable access to private fields
+            .enable(MapperFeature.USE_ANNOTATIONS)


While the defaults have changed, I think all of these features and behavior were present in 2.x, correct?

bitwiseman · 2026-01-23T19:26:35Z

src/main/java/org/kohsuke/github/GitHubClient.java

    private static final int DEFAULT_MINIMUM_RETRY_MILLIS = DEFAULT_MAXIMUM_RETRY_MILLIS;
    private static final Logger LOGGER = Logger.getLogger(GitHubClient.class.getName());
-    private static final ObjectMapper MAPPER = new ObjectMapper();
+    private static final JsonMapper MAPPER = JsonMapper.builder()


JsonMapper is a subclass of ObjectMapper correct?

bitwiseman · 2026-01-23T20:02:38Z

pom.xml

+        <scope>import</scope>
+      </dependency>
+      <!-- Jackson 3.0 requires jackson-annotations 2.20 -->
+      <dependency>


Delete this and keep the com.fasterxml.jackson.jackson-bom import. It is only dependency management, so it should generally be fine. There doesn't appear to be overlaping dependencies between com.fasterxml.jackson.jackson-bom and tools.jackson.jackson-bom.

bitwiseman · 2026-01-23T20:30:10Z

@pvillard31
Thanks for contributing!

It looks like Jackson 2.20 and 3.x can exist side-by-side. As such, I'd like to ask you to go about this change a different way.

First, it looks like many of the changes in this PR could be done while still depending on 2.20. Let's make all those changes first. Basically, start a new branch, take the changes from this PR, revert the Jackson version in the POM back to 2.20, then keep as many of the code changes as possible from this PR. I've noted at least a few of them.

Second, take all the remaining places where the code would change between 2.20 and 3.x and refactor them into GitHubJackson GitHubJacksonFactory (with GitHubJackson2 and GitHubJackson3 classes implementing the behaviors for each version).

Similar to DefaultGitHubConnector in the 1.x:

github-api/src/main/java/org/kohsuke/github/internal/DefaultGitHubConnector.java

Lines 53 to 57 in 9dd29b8

    
           try { 
        
               return new HttpClientGitHubConnector(); 
        
           } catch (UnsupportedOperationException | LinkageError e) { 
        
               return new GitHubConnectorHttpConnectorAdapter(HttpConnector.DEFAULT); 
        
           }

This second part will probably include creating one or more new exception GitHubJacksonException classes to encapsulate the version-specific exceptions.

For testing, we can have a run similar to the okhttp in behavior, where the version used is controlled by a property.

I know this is more work, but we need to continue to support 2.x for a while longer.

Move to Jackson 3

b1a8d76

pvillard31 mentioned this pull request Dec 21, 2025

Compatibility issue with Jackson 2.20 and above #2166

Open

bitwiseman reviewed Dec 24, 2025

View reviewed changes

bitwiseman reviewed Jan 23, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Move to Jackson 3 #2173

Move to Jackson 3 #2173

Uh oh!

pvillard31 commented Dec 21, 2025 •

edited

Loading

Uh oh!

bitwiseman Dec 24, 2025

Uh oh!

pvillard31 Dec 24, 2025

Uh oh!

bitwiseman commented Dec 24, 2025

Uh oh!

pvillard31 commented Dec 24, 2025

Uh oh!

yeikel commented Jan 14, 2026

Uh oh!

bitwiseman Jan 23, 2026

Uh oh!

bitwiseman Jan 23, 2026

Uh oh!

bitwiseman Jan 23, 2026

Uh oh!

bitwiseman Jan 23, 2026

Uh oh!

bitwiseman Jan 23, 2026

Uh oh!

bitwiseman Jan 23, 2026

Uh oh!

bitwiseman commented Jan 23, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Move to Jackson 3 #2173

Are you sure you want to change the base?

Move to Jackson 3 #2173

Uh oh!

Conversation

pvillard31 commented Dec 21, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Description

Before submitting a PR:

When creating a PR:

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

bitwiseman commented Dec 24, 2025

Uh oh!

pvillard31 commented Dec 24, 2025

Uh oh!

yeikel commented Jan 14, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

bitwiseman commented Jan 23, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

pvillard31 commented Dec 21, 2025 •

edited

Loading