Migration to Java 21 and Spring Boot 3.4

Please add any missing hints to this document!

See TC’s approved Officially Supported Technologies / Sunflower document.

Help

Ask on #development Slack channel if a module doesn’t build on Java 21 and/or Spring Boot 3.4.

Jenkinsfile

In Jenkinsfile change the buildNode from java17 to java21:

buildNode = 'jenkins-agent-java21'

Dockerfile

In Dockerfile change the container from opendjk17 to openjdk21:

FROM folioci/alpine-jre-openjdk21:latest

For details see https://github.com/folio-org/folio-tools/tree/master/folio-java-docker/openjdk21

GitHub Actions

A few projects use a Java in GitHub Actions workflow, check the .github/workflows directory. Upgrade java-version from 17 to 21:

- uses: actions/setup-java@v4
  with:
    distribution: 'temurin'
    java-version: '21'

POM Files

If declared, be sure to change the Java version and source/target compilation versions. This can be done under the main properties block:

<java.version>21</java.version>
<maven.compiler.source>21</maven.compiler.source>
<maven.compiler.target>21</maven.compiler.target>

Note: for this to work, be sure that the source/target versions are not overridden in the maven-compiler-plugin configuration.

Mockito

See https://javadoc.io/doc/org.mockito/mockito-core/latest/org/mockito/Mockito.html#0.3 how to enable instrumentation of Mockito’s inline-mock-maker if it doesn’t work with Java 21.

Snippets that also work in IDEs:

  <properties>
    <argLine></argLine>
    <mockito.version>5.16.0</mockito.version>
  </properties>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>3.5.2</version>
        <configuration>
          <argLine>
            @{argLine}
            -javaagent:${settings.localRepository}/org/mockito/mockito-core/${mockito.version}/mockito-core-${mockito.version}.jar
            -Xshare:off
          </argLine>
        </configuration>
      </plugin>
    </plugins>
  </build>

Spring Boot

Upgrade the spring-boot-starter-parent version to the latest 3.4 version, find the version on https://github.com/spring-projects/spring-boot/tags

Replace javax.annotation.PostConstruct with jakarta.annotation.PostConstruct.

Add null argument to buildConsumerProperties() and buildProducerProperties() of KafkaProperties (example).

Replace @MockBean with @MockitoBean and @SpyBean with MockitoSpyBean.

Change Actuator settings management.endpoints.enabled-by-default to management.endpoints.access.default (The Boolean values change to none, read-only, and unrestricted).

Change Actuator settings from management.endpoint.<id>.enabled to management.endpoint.<id>.access.

The Spring-Boot-3.4-Release-Notes describe further details useful for migration.

ObjectOptimisticLockingFailureException

After upgrade to Spring Boot 3.4 some tests fail with

org.springframework.orm.ObjectOptimisticLockingFailureException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)

if an entity has

@Id
@GeneratedValue(strategy = GenerationType.UUID)
private UUID id;

and tests initialize the id with some UUID.

Solution: Set id to null, or don’t initialize it.

Learn more at https://stackoverflow.com/questions/79228209/spring-boot-3-4-0-lets-integration-tests-with-jpa-hibernate-fail

Openfeign

spring-cloud-starter-openfeign 4.2.x is required for Spring Boot 3.4.x, use the latest patch version: https://github.com/spring-cloud/spring-cloud-openfeign/tags

Migrated repositories

https://folio-org.atlassian.net/browse/FOLIO-4182 – Epic Sunflower 2025 R1 - Upgrade to Java 21 and Spring Boot 3.4

In August 2024 some FOLIO modules and FOLIO libraries have had been migrated to Spring Boot 3.4 as a proof of concept to demonstrate that only small changes are needed:

https://github.com/folio-org/mod-bulk-operations/compare/master...julianladisch:mod-bulk-operations:spring-boot-3.4	Build result: success
https://github.com/folio-org/mod-circulation-item/pull/29/files	Build result: success
https://github.com/folio-org/mod-data-export-worker/compare/master...julianladisch:mod-data-export-worker:spring-boot-3.4	Build result: success
https://github.com/folio-org/mod-inn-reach/compare/master...julianladisch:mod-inn-reach:spring-boot-3.4	Build result: success
https://github.com/folio-org/mod-search/compare/master...julianladisch:mod-search:spring-boot-3.4	Build result: success
https://github.com/folio-org/folio-spring-support/compare/master...julianladisch:folio-spring-support:FOLSPRINGS-161-spring-boot-3.4	Build result: success
https://github.com/folio-org/folio-service-tools/compare/master...julianladisch:folio-service-tools:spring-boot-3.4	Build result: success

What is Spring Boot’s milestone and release candidate history?

v3.5.x:

2025-01-23 v3.5.0-M1

v3.4.x:

2024-11-21 v3.4.0
2024-10-26 v3.4.0-RC1
2024-09-19 v3.4.0-M3
2024-08-22 v3.4.0-M2
2024-07-18 v3.4.0-M1

v3.3.x:

2024-05-23 v3.3.0
2024-04-19 v3.3.0-RC1
2024-04-05 v3.3.0-M3
2024-02-22 v3.3.0-M2
2024-01-19 v3.3.0-M1

v3.2.x:

2023-11-23 v3.2.0
2023-11-03 v3.2.0-RC2
2023-10-20 v3.2.0-RC1
2023-09-21 v3.2.0-M3
2023-08-24 v3.2.0-M2
2023-07-20 v3.2.0-M1

v3.1.x:

2023-05-19 v3.1.0
2023-05-05 v3.1.0-RC2
2023-04-22 v3.1.0-RC1
2023-04-24 v3.1.0-M2
2023-02-24 v3.1.0-M1

Spring Boot has always been released on the planned date.