Question

I have the following code:

private static final Set<String> allowedParameters;
static {
    Set<String> tmpSet = new HashSet();
    tmpSet.add("aaa");
    allowedParameters = Collections.unmodifiableSet(tmpSet);
}

And it cause:

Note: mygame/Game.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

And when I recompile with the suggested option I see a pointer (^) pointing at “new” in front of HashSet();.

Does anybody know what is going on here?

Answer 1

Yes, you’re creating a new HashSet without stating what class it should contain, and then asserting that it contains strings. Change it to

 Set<String> tmpSet = new HashSet<String>();