End of first-class JDK 6 support
It is about time: The official end of of commercial JDK 6 support is coming up soon, with Oracle declaring December 2018 and IBM declaring April 2018 as the end of their extended support.
From a Spring perspective, we take the opportunity to deemphasize JDK 6 support on our end. We'll keep tolerating a JDK 6 runtime in the entire Spring Framework 4.3.x line for all further maintenance releases. However, we won't make compromises for JDK 6 anymore, asking you to upgrade to JDK 7+ for fixes that we'd have to work around specifically for JDK 6 on our end.
Even for JDK 7, we expect a recent patch…