In order to be able to run Java 8 API compatibility tests, I'm going to push a new set of Jenkins configurations for Spark's test and PR builders so that those jobs use a Java 8 JDK. I tried this once in the past and it seemed to introduce some rare, transient flakiness in certain tests, so if anyone observes new test failures please email me and I'll investigate right away.
Note that this change has no impact on Spark's supported JDK versions and our build will still target Java 7 and emit Java 7 bytecode; the purpose of this change is simply to allow the Java 8 lambda tests to be run as part of PR builder runs. - Josh
