Integration tests fail: test-service-broker.jar incompatible with java-buildpack v5 (JDK 17 default)

[jorbaum]

On March 20-21, 2026, the java-buildpack main branch was updated to v5.0.1, which defaults to JDK 17 (up from JDK 8 in v4.x).

The integration tests hardcode buildpack("https://github.com/cloudfoundry/java-buildpack.git") in ApplicationUtils.java:230, so they now get JDK 17. The bundled test-service-broker.jar is a Spring Boot 1.5.16 app (built ~2018) that relies on CGLIB reflective access incompatible with JDK 17's module system. The app crashes on startup with InaccessibleObjectException, causing DelayTimeoutException and failing all tests that depend on serviceBrokerId.

Workaround

Add --add-opens flags to the service broker environment in ServiceBrokerUtils.pushServiceBrokerApplication():

env.put("JAVA_OPTS",
    "--add-opens java.base/java.lang=ALL-UNNAMED"
        + " --add-opens java.base/java.io=ALL-UNNAMED");

Potential longer-term fixes

• Rebuild test-service-broker.jar with a modern Spring Boot version
• Pin the buildpack to a version tag or use the system buildpack instead of tracking main