- Java 100%
Ron Smits
280e6a37d9
Multi-module Gradle project demonstrating the difference between platform() and enforcedPlatform() for BOM dependency management. - platform-bom: BOM with bcprov-jdk18on:1.78 constraint - lib-c: library depending on bcprov-jdk18on:1.80 (newer than BOM) - app-a: consumer using platform() — Gradle picks 1.80 via highest-version - app-b: consumer using enforcedPlatform() — BOM forces 1.78 |
||
|---|---|---|
| app-a | ||
| app-b | ||
| gradle/wrapper | ||
| lib-c | ||
| platform-bom | ||
| .gitignore | ||
| build.gradle.kts | ||
| gradlew | ||
| gradlew.bat | ||
| opencode.json | ||
| README.md | ||
| settings.gradle.kts | ||
Gradle Platform Demo
Demonstrates the difference between Gradle's platform() and enforcedPlatform() for dependency management.
Structure
| Module | Purpose |
|---|---|
platform-bom |
BOM defining bcprov-jdk18on:1.78 as a constraint |
lib-c |
Library depending on bcprov-jdk18on:1.80 (newer than BOM — makes the contrast visible at runtime) |
app-a |
Consumer using platform() — BOM version is a recommendation |
app-b |
Consumer using enforcedPlatform() — BOM version is forced |
How to Run
Build the project
./gradlew build
Run both apps
./gradlew :app-a:run
./gradlew :app-b:run
Different output, by design:
| App | Mechanism | Runtime output |
|---|---|---|
app-a |
platform() |
BouncyCastle registered: version=1.8 |
app-b |
enforcedPlatform() |
BouncyCastle registered: version=1.78 |
app-a gets 1.80 (runtime shows 1.8) because platform() only adds the BOM constraint to the resolution graph — Gradle's highest-version strategy then picks 1.80 (from lib-c) over 1.78 (from the BOM). The BOM was only a recommendation.
app-b gets 1.78 because enforcedPlatform() overrides any other version declaration — lib-c's transitive 1.80 is forced back down to the BOM's 1.78.
Confirm via dependency insight
app-a (platform()):
./gradlew :app-a:dependencyInsight --dependency bcprov-jdk18on --configuration runtimeClasspath
Output shows 1.80 selected, with the 1.78 constraint from platform-bom listed but not winning — Gradle's highest-version strategy beat the recommendation.
app-b (enforcedPlatform()):
./gradlew :app-b:dependencyInsight --dependency bcprov-jdk18on --configuration runtimeClasspath
Output shows 1.78 selected with Selection reasons: By constraint, Forced — the BOM version is explicitly enforced, overriding the transitive 1.80 from lib-c.
Full dependency trees
./gradlew :app-a:dependencies --configuration runtimeClasspath
./gradlew :app-b:dependencies --configuration runtimeClasspath
Key Takeaway
platform()— BOM constraints participate in resolution alongside other versions. Gradle still decides.enforcedPlatform()— BOM constraints override any other version declaration. The BOM is the single source of truth.