It would be nice if the hint which warns of comparing Strings using == or != provided a fix which changed the expression
to use the equals() method instead.

Original expression:
  (str1 == str2)
Fix:
  (str1.equals(str2))

A truly equivalent fix would actually ensure that the new expression always evaluates to the same value as the original
(and avoids the potential NPE).  Such a Fix could incorporate a ternary null check.  For those who dislike ternary
operators, a third Fix could be offered.

Original expression:
  (str1 == str2)
Fix 1 (no null check):
  (str1.equals(str2))
Fix 2 (ternary null check):
  ((str1 == null) ? (str2 == null) : str1.equals(str2))
Fix 3 (non-ternary null check):
  (((str1 == null) && (str2 == null)) || ((str1 != null) && str1.equals(str2)))

Similarly, != would be handled thusly:

Original expression:
  (str1 != str2)
Fix 1 (no null check):
  (!str1.equals(str2))
Fix 2 (ternary null check):
  ((str1 == null) ? (str2 != null) : !str1.equals(str2))
Fix 3 (non-ternary null check):
  (((str1 == null) && (str2 != null)) || ((str1 != null) && !str1.equals(str2)))