As some of you may know, sun.reflect.Reflection#getCallerClass(int) was removed in Java 8 (it was replaced with no-arg Reflection#getCallerClass(), which uses non-public @CallerSensitive). This resulted in LOG4J2-245 [1] (EmptyStackException on Java 8), which was resolved with using a backup option (SecurityManager#getClassContext()) in the hopes that a replacement would be found. I have been actively involved in discussions on the Java 8 Core Libraries mailing list to replace this behavior with a public API in Java 8 [2,3].
It has now come to my attention that the changes to Reflection#getCallerClass(...) have been back-ported to Java 7 now [4,5] (effective 1.7.0_25, released in the last week or so). Since it's a non-public API, they're free to do this any time they want, but it will cause a nightmare for Log4j users using 1.7.0_25 and higher. Here are the exact changes that were made: 1) Added no-arg Reflection#getCallerClass() that uses back-ported @CollerSensitive. 2) Left Reflection#getCallerClass(int) in place, but it now THROWS an UnsupportedOperationException (which is even worse ... the fix for LOG4J2-245 won't pick this up and make it work for 1.7.0_25+ users). 3) In Java 7 _only_ (won't work for Java 8) users can specify jdk.reflect.allowGetCallerClass system property to enable Reflection#getCallerClass(int). I submit this will not be an option our users are willing to accept, but it is a temporary workaround. Here's hoping they add a public API in Java 8 to make what we're using this for easier (I'm pushing as hard as I can), but it looks like Java 7 is broke for good. We should probably add in a check so that getCallerClass is not used unless Java major version is 6. I do not know how this change will impact Log4j 1.x. Hopefully it won't. Nick [1] https://issues.apache.org/jira/browse/LOG4J2-245 [2] http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-June/018049.html [3] http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-June/018353.html [4] http://mail.openjdk.java.net/pipermail/jdk7u-dev/2013-June/006791.html [5] http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-June/018349.html --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
