cdm/src/main/java/ucar/nc2/util/DiskCache2.java
static public void exit() {
    if (timer != null) {
      timer.cancel();
      System.out.printf("DiskCache2.exit()%n");
    }
    timer = null;
  }
static public void exit() {
    if (timer != null) {
      timer.cancel();
      System.out.printf("DiskCache2.exit()%n");
    }
    timer = null;
  }
Be sure to call this when your application exits, otherwise your process may not exit without being killed.