feat: migrate to jackson 3

[vpelikh]

Description

This PR consists of two commits:

• update to java 17 (minimum version for jackson 3)
• update to jackson 3

Fixes: #4991

Type of Change

• 🐛 Bug fix
• ✨ New feature
• ♻️ Refactor (non-breaking change)
• 🧪 Tests
• 📝 Documentation
• 🧹 Chore (build or tooling)

Checklist

• I have added/updated tests as needed
• I have added/updated documentation where applicable
• The PR title is descriptive
• The code builds and passes tests locally
• I have linked related issues (if any)

Screenshots / Additional Context

[cbot59]

I think we need to introduce constructor for ModelResolver(JsonMapper) and deprecate the old constructor so the newer release requires user to Jackson3 instead.

currently I have such usage on ModelResolver when using springdoc-openapi

my first attempt to migrate to Jackson3 would be

public ModelResolver modelResolver(JsonMapper jsonMapper) {
        return new ModelResolver(jsonMapper);
    }

as it is more straightforward

[vpelikh]

I have removed many of the changes associated with java 17, so the PR is now much smaller.

@cbot59, thanks for the comment! JsonMapper is a descendant of ObjectMapper, so return new ModelResolver(jsonMapper); should work without a new constructor.

[WilliamAGH]

Hey everyone -- thanks to @vpelikh, we now have Jackson 3 and Java 17 support.

But I didn't want to wait, so I have it available here! His branch is available as a dependency, just add this to your build.gradle file or pom.xml equivalent:

configurations.all {
    resolutionStrategy.dependencySubstitution {
        substitute(module("io.swagger.core.v3:swagger-core-jakarta"))
            .using(module("com.github.WilliamAGH.swagger-core:swagger-core-jakarta:jackson-3-SNAPSHOT"))
        substitute(module("io.swagger.core.v3:swagger-models-jakarta"))
            .using(module("com.github.WilliamAGH.swagger-core:swagger-models-jakarta:jackson-3-SNAPSHOT"))
        substitute(module("io.swagger.core.v3:swagger-annotations-jakarta"))
            .using(module("com.github.WilliamAGH.swagger-core:swagger-annotations-jakarta:jackson-3-SNAPSHOT"))
    }

[piotrooo]

@cbot59, thanks for the comment! JsonMapper is a descendant of ObjectMapper, so return new ModelResolver(jsonMapper); should work without a new constructor.

No, it doesn't, because the ObjectMapper used by Swagger comes from the com.fasterxml.jackson.databind package (Jackson v2), while in v3 the JsonMapper comes from tools.jackson.databind.

[KP-EV]

Any update on this?

[larsf96]

Any chance that a maintainer takes a look here?
Is there any workaround to use Spring Boot 4 with SpringDoc 3 without waiting for this?

[WilliamAGH]

Any chance that a maintainer takes a look here? Is there any workaround to use Spring Boot 4 with SpringDoc 3 without waiting for this?

Yes, I’ve had this workaround in use in production for the last 2 weeks:

#5031 (comment)

[larsf96]

configurations.all {
resolutionStrategy.dependencySubstitution {
substitute(module("io.swagger.core.v3:swagger-core-jakarta"))
.using(module("com.github.WilliamAGH.swagger-core:swagger-core-jakarta:jackson-3-SNAPSHOT"))
substitute(module("io.swagger.core.v3:swagger-models-jakarta"))
.using(module("com.github.WilliamAGH.swagger-core:swagger-models-jakarta:jackson-3-SNAPSHOT"))
substitute(module("io.swagger.core.v3:swagger-annotations-jakarta"))
.using(module("com.github.WilliamAGH.swagger-core:swagger-annotations-jakarta:jackson-3-SNAPSHOT"))
}

This does not work for me:

***************************
APPLICATION FAILED TO START
***************************

Description:

An attempt was made to call a method that does not exist. The attempt was made from the following location:

    org.springdoc.core.providers.ObjectMapperProvider.<init>(ObjectMapperProvider.java:75)

The following method did not exist:

    'com.fasterxml.jackson.databind.ObjectMapper io.swagger.v3.core.util.Json31.mapper()'

The calling method's class, org.springdoc.core.providers.ObjectMapperProvider, was loaded from the following location:

    jar:file:/application/BOOT-INF/lib/springdoc-openapi-starter-common-3.0.1.jar!/org/springdoc/core/providers/ObjectMapperProvider.class

The called method's class, io.swagger.v3.core.util.Json31, is available from the following locations:

    jar:file:/application/BOOT-INF/lib/swagger-core-jakarta-jackson-3-52d4c245bb-1.jar!/io/swagger/v3/core/util/Json31.class
    jar:file:/application/BOOT-INF/lib/swagger-core-jakarta-2.2.41.jar!/io/swagger/v3/core/util/Json31.class

The called method's class hierarchy was loaded from the following locations:

    io.swagger.v3.core.util.Json31: file:/application/BOOT-INF/lib/swagger-core-jakarta-jackson-3-52d4c245bb-1.jar


Action:

Correct the classpath of your application so that it contains compatible versions of the classes org.springdoc.core.providers.ObjectMapperProvider and io.swagger.v3.core.util.Json31

[vpelikh]

@daniel-kmiecik @Mattias-Sehlstedt @ewaostrowska, hey! I see you've done the last commits to this repository. Can anyone check out this PR?

[Mattias-Sehlstedt]

Hi @vpelikh, I am only a contributor, so I can unfortunately not do anything to help. But the other two are maintainers and will hopefully assist you.

[piotrooo]

@MichakrawSB Is there any ETA for this feature? Can we please prioritize this?

[KP-EV]

It would be really great if you could prioritize this 🙏

[fenston]

Is this PR not progressing?

[lordarnoud]

Any information on this yet? Will this also make it work with the newest springboot and java 26?

[jochenberger]

I'm running the current version with latest Spring Boot/Jackson 3 on Java 26 without issues.

[piotrooo]

I'm running the current version with latest Spring Boot/Jackson 3 on Java 26 without issues.

Yes, it works. However, you probably need to add Jackson 2 compatibility support using the deprecated classes. It does work, but it is not an ideal solution.

[mzhafez]

Is there any plan on merging this or maybe adding this to the next major version instead?

[lbenedetto]

Going to be forced to ditch swagger and find another solution soon 😅

Spring Boot 3.5.x OSS Support (End of Life) ends on June 30, 2026. After this date, community-driven security patches and bug fixes will cease.

[BranislavMalo]

Hey, any update on this?

this has been open since january 1st and there’s a lot of interest here compared to most PRs, but it’s still just sitting in “review required” while multiple releases went out

is this actually planned to be merged anytime soon or is it blocked on something?

[jochenberger]

Yes, it works. However, you probably need to add Jackson 2 compatibility support using the deprecated classes.

No, you don't. Just upgrade Spring Boot and migrate your code to Jackson 3. As long as swagger-core depends on Jackson 2, they will pull it in and just use it.

I wonder how many people give up before even trying to do the update.

[zqq90]

I'm running the current version with latest Spring Boot/Jackson 3 on Java 26 without issues.

@jochenberger

I suspect you might not have used certain annotations from the jackson-databind package, such as JsonNaming.

Or you may have added both Jackson 2 and Jackson 3 annotations at the same time during the migration.

For example:

@tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
@com.fasterxml.jackson.databind.annotation.JsonNaming(com.fasterxml.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
public class SampleVO {

If that's the case, it's really a nagging annoyance.

[jochenberger]

Good point @zqq90, I'm indeed not using any of those.