ReflectUtils produces Warning in Spring Boot 2.0.0.M6 and Java 9.0.1 [SPR-16236]

[spring-projects-issues]

Myungwoon Oh opened SPR-16236 and commented

I made a new Spring Boot 2.0.0.M6 + Java 9.0.1 project to study WebFlux.

When I run application, it runs without Error but with some Warnings related to ReflectUtils.

See https://gist.github.com/HomoEfficio/5075df52298baf8188e6847b0b9cf914#file-springboot2-java9-webflux-console-L18

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Affects: 5.0.1

Reference URL: https://gist.github.com/HomoEfficio/5075df52298baf8188e6847b0b9cf914

Attachments:

• build.gradle (1.05 kB)

Issue Links:

• MethodHandles.Lookup.defineClass for CGLIB class definition purposes [SPR-15859] #20414 MethodHandles.Lookup.defineClass for CGLIB class definition purposes ("duplicates")

[spring-projects-issues]

Juergen Hoeller commented

We are tracking this in #20414: It's simply our repackaged CGLIB trying its traditional (and fully backwards-compatible) code path first, falling back to a separate code path which happens to work fine on JDK 9 as well.

For the time being, the cleanest way out is to start your JVM with --illegal-access=deny. This may sound strange but actually rejects the traditional code path at runtime, enforcing the fallback variant, without any warning logged.