Java not greater than operator?

Peace be upon you <3

Say we have:

String str = "hello";

Now I want to find using an if statement that the length of str is not greater than 5.

I tried These but it's throwing compiler exceptions:

if(!str.length() > 5) doSomething();
if(!(str.length()) > 5) doSomething();
if(!(str.length() > 5)) doSomething();

Question: How do I tell that the length of str is not greater or smaller than a certain number.