how i bgga closures antecedent customary mac jdk6?

i am perplexing an existent jdk 6 (standard mac os x leopard). illustration formula i'm compiling bgga tutorial:

public stationary vacant main(string[] args) {
  // duty arguments; relapse value always 42
  int answer = { => 42 }.invoke();
  system.out.println(answer);
}

i have attempted following, zero work:

1. copied closures.jar /system/library/frameworks/javavm.framework/versions/1.6/home/lib


2. ran javac -xbootclasspath/a:/path/to/closures.jar


3. ran javac -j-xbootclasspath/a:/path/to/closures.jar


4. tried obscure ganymede defining possess component library attaching digest formula utilizing bgga.

in 4 cases, i gathering errors, indicating compiler collect adult closures.jar bootstrap classpath. i'd unequivocally operative eclipse, during unequivocally slightest maven. thanks!