NullPointerException should be avoided, not caught. Any situation in which NullPointerException is explicitly caught can easily be converted to a null test, and any behavior being carried out in the catch block can easily be moved to the "is null" branch of the conditional.

Compliant Solution

public int lengthPlus(String str) {
  int len = 2;

  if (str != null) {
    len += str.length();
  }
  else {
    log.info("argument was null");
  }
  return len;
}

See

• MITRE, CWE-395 - Use of NullPointerException Catch to Detect NULL Pointer Dereference
• CERT, ERR08-J - Do not catch NullPointerException or any of its ancestors