Can't use Java 17 with 2.9-M6 milestone if application is using ehcache

[yle-heikkij]

Play Version

2.9.0-M6

API

Scala

Operating System

MacOS 13.4.1 (22F82)

JDK

openjdk version "17.0.6" 2023-01-17
OpenJDK Runtime Environment Temurin-17.0.6+10 (build 17.0.6+10)
OpenJDK 64-Bit Server VM Temurin-17.0.6+10 (build 17.0.6+10, mixed mode)

Expected Behavior

We have small Play Framework application I tried to run with 2.9.0-M6 in Java 17 environment. App uses ehcache. Everything works fine if Java version is 11

Actual Behavior

java.lang.reflect.InaccessibleObjectException: Unable to make field private final byte[] java.lang.String.value accessible: module java.base does not "opens java.lang" to unnamed module @61fbe4c1
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:354)
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
	at java.base/java.lang.reflect.Field.checkCanSetAccessible(Field.java:178)
	at java.base/java.lang.reflect.Field.setAccessible(Field.java:172)
	at net.sf.ehcache.pool.sizeof.ObjectGraphWalker.getAllFields(ObjectGraphWalker.java:271)

-->

[xuwei-k]

Maybe playframework should update to ehcache version 3.x 🤔

• https://github.com/ehcache/ehcache3
• https://github.com/ehcache/ehcache2

• playframework/project/Dependencies.scala

  Lines 301 to 303 in 63c8845

  	val ehcacheVersion = "2.10.9.2"
  	val playEhcacheDeps = Seq(
  	"net.sf.ehcache" % "ehcache" % ehcacheVersion,

[ihostage]

@yle-heikkij Can you try to add this JVM parameter --add-opens=java.base/java.lang=ALL-UNNAMED to your run application command?

@xuwei-k I agree with you, we should add upgrade Ehcache into our plans 📝

[yle-heikkij]

@yle-heikkij Can you try to add this JVM parameter --add-opens=java.base/java.lang=ALL-UNNAMED to your run application command?

Yes, I tested and error went away

[mkurz]

Yeah, ehcache should be upgraded, however this will not make it into 2.9 anymore. Tagged for next major release.

[ben-manes]

fyi ehcache2 is fully end of life (no maintenance or critical/security fixes)

[mkurz]

fyi, we are thinking about to remove play ehcache support. You can either provide a pull request to upgrade to ehcache 3 or you can of course also write a Play module and host it in your own repo.
No one from the Play team will work on that however, so if no one steps forward, we will eventually delete the current Play ehcache module which is still based on ehcache 2.