Exercise – Comparing String.indexOf() and StringUtils.indexOf()

What is the difference between the indexOf() method of the String class and the indexOf() method of the StringUtils class?

Answer

The indexOf() method of the String class does not handle null. Here is some demo code:

String s = null;
int i = StringUtils.indexOf(s, "abc");     //return -1
s.indexOf("abc");                          //throws NullPointerException