Java 25 Upgrade

Upgrade Java projects to Java 25 with all required dependency updates.

When to Use

Project needs to upgrade from Java 21 to Java 25
Need features from Java 25 (records, pattern matching improvements, etc.)
Planning to stay on latest LTS-adjacent releases
When asked to "prepare for Java 25" or "upgrade to Java 25"

Skill Contents

Available Resources

📚 references/ - Detailed documentation

preparation

Prerequisites

Spring Boot 3.5.x - Upgrade to Spring Boot 3.5.x first
sdkman - For managing Java versions
Java 25 Temurin - Install via: sdk install java 25.0.1-tem

Target Versions

Component	Version	Notes
Java	25	Target JDK
Gradle	9.2.1	Major version required
Groovy	5.0.3	Java 25 requires Groovy 5.x
Spock	2.4-groovy-5.0	Must match Groovy version
Lombok	1.18.42	Java 25 bytecode support
Lombok Plugin	9.2.0	Freefair plugin for Gradle 9.2.1
Spotless	8.1.0	Gradle 9 compatible
SonarQube Plugin	7.2.2.6593	Gradle 9 compatible
ByteBuddy	1.17.5+	ASM 9.8 for Java 25

⚠️ DO NOT Upgrade

protobuf: Keep existing version
grpc: Keep existing version
Spring Boot: Keep at 3.5.x (already upgraded)

Workflow

Phase 1: Prepare (Local Validation)

# Install and use Java 25
sdk install java 25.0.1-tem
sdk use java 25.0.1-tem

# Upgrade Gradle wrapper
./gradlew wrapper --gradle-version=9.2.1

# Update version catalog (see below)
# Build and test locally
./gradlew clean build test

Phase 2: Commit (After Tests Pass)

Only commit the toolchain change after all tests pass locally.

Version Catalog Updates

# gradle/libs.versions.toml
[versions]
groovy = "5.0.3"
spock = "2.4-groovy-5.0"
lombok = "1.18.42"
bytebuddy = "1.17.5"  # If defined

[plugins]
lombok = "io.freefair.lombok:9.2.0"
spotless = "com.diffplug.spotless:8.1.0"
sonarqube = "org.sonarqube:7.2.2.6593"

Java Toolchain Configuration

// root build.gradle
allprojects {
    plugins.withType(JavaPlugin).configureEach {
        java {
            toolchain {
                languageVersion = JavaLanguageVersion.of(25)
                vendor = JvmVendorSpec.ADOPTIUM
            }
        }
    }
}

⚠️ Critical: Do NOT Use groovy-all

The groovy-all:5.0.3 artifact has broken transitive dependencies:

// ❌ NEVER: groovy-all has broken transitive deps
testImplementation 'org.apache.groovy:groovy-all:5.0.3'

// ✅ CORRECT: Let spock-core bring in Groovy 5.0.3 transitively
testImplementation libs.spock.core
testImplementation libs.spock.spring  // if using Spring

Override Spring Boot's Groovy Version

// root build.gradle
allprojects {
    ext['groovy.version'] = libs.versions.groovy.get()
}

References

Reference	Content
references/preparation.md	Detailed preparation steps and prerequisites

Related Skills

spring-boot-3-5 - Must upgrade first
gradle-9 - Gradle 9 upgrade patterns

java-25