This line is in the form of
String str = ...
str.equals("someOtherString");
//or
str.compareTo("someOtherString");
A NullPointerException may occur if the String variable str is null. If instead the code was restructured to
String str = ...
"someOtherString".equals(str);
//or
"someOtherString".compareTo(str);
that is, call equals() or compareTo() on the string literal, passing the variable as an argument, this exception could never happen as both equals() and compareTo() check for null.