Update to Spring Boot 4

[raynigon]

No description provided.

[Copilot]

Pull request overview

This pull request upgrades the project from Spring Boot 3 to Spring Boot 4, which includes a major migration from Jackson 2.x (com.fasterxml.jackson) to Jackson 3.x (tools.jackson). The changes also update test dependencies (Groovy 5.0.3, Spock 2.4) and bump the project version to 4.0.0-SNAPSHOT.

Key Changes

• Migration from Jackson 2.x to Jackson 3.x with complete package namespace changes
• Updated Spring Boot from 3.5.7 to 4.0.1
• Replaced deprecated Jackson APIs (JsonSerializer/JsonDeserializer → ValueSerializer/ValueDeserializer, SerializerProvider → SerializationContext)
• Updated test framework dependencies and migrated tests to use RestClient instead of TestRestTemplate

Reviewed changes

Copilot reviewed 30 out of 30 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
buildSrc/build.gradle.kts	Updates Spring Boot Gradle plugin to 4.0.1
buildSrc/src/main/kotlin/unit-api.test.gradle.kts	Updates Groovy to 5.0.3 and Spock to 2.4, adds JUnit platform launcher
buildSrc/src/main/kotlin/unit-api.spring-conventions.gradle.kts	Updates Spock Spring integration to 2.4
unit-api-jackson/build.gradle	Migrates Jackson dependency from com.fasterxml to tools.jackson 3.0.3
unit-api-jackson/src/main/java/.../serializer/QuantitySerializer.java	Migrates to ValueSerializer API and SerializationContext
unit-api-jackson/src/main/java/.../deserializer/QuantityDeserializer.java	Migrates to ValueDeserializer API
unit-api-jackson/src/main/java/.../deserializer/extractor/*.java	Updates to use tools.jackson packages and new API methods
unit-api-jackson/src/main/java/.../exception/*.java	Updates exception hierarchy from JsonMappingException to DatabindException/InvalidFormatException
unit-api-jackson/src/main/java/.../config/UnitApiFeature.java	Updates FormatFeature import to tools.jackson
unit-api-jackson/src/main/java/.../UnitApiModule.java	Updates module imports to tools.jackson
unit-api-jackson/src/test/groovy/.../QuantitySerializerSpec.groovy	Migrates tests to JsonMapper.builder() pattern, updates mocks for new API
unit-api-jackson/src/test/groovy/.../helpers/DummyContext.groovy	Updates deserialization context construction for new API
unit-api-jackson/src/test/groovy/.../exception/UnitExceptionSpec.groovy	Updates exception tests for new error message format
unit-api-jackson/src/test/groovy/.../deserializer/*.groovy	Updates imports and method calls for new Jackson API
spring-boot-jackson-starter/build.gradle	Adds RestClient dependency for testing
spring-boot-jackson-starter/src/test/groovy/.../*.groovy	Migrates tests from TestRestTemplate to RestClient
spring-boot-springdoc-starter/src/test/groovy/.../UnitApiPropertyCustomizerSpec.groovy	Adds SimpleType test helper with containedTypeName method
spring-boot-jpa-starter/src/test/groovy/.../QuantityTypeSpec.groovy	Renames static imports to avoid conflicts
gradle.properties	Updates version to 4.0.0-SNAPSHOT

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[Grannath]

I am a little worried about those references to the old Jackson libraries. Can we test this somehow with a "real" runtime classpath?

[raynigon]

@Grannath The Annotations are still the old ones, there are no new annotations for jackson3.

What do you mean by "real" runtime?
Thats what the Integration tests are for, arent they?