I am on Java 7 now!

OK,

it took me some going back and forth, and pulling out some hair, but it's done. I am on Java 7.

The trick was probably not in the JDK itself, but in the switch: change java and JAVA_HOME, then force your build environment and your IDE (NetBeans) to pick up the changes. In the IDE, I had to pretend to rename and refactor packages, then bring them back. Finally, I got it, so now my pom.xml lists both source and target as Java 7, that is,

source=1.7
target=1.7

and even minor language changes work, like this switch with String's

switch (mycase) {
  case "aha!": {

  }
  case "uhu!": {

  }
}

There may be more glitches, but based on my experience, you can resolve all.