Java substring check

Question

I have a String2. I want to check whether String2 exists in String1. String1's length can be less or greater or equal than String2. Also String2 can be null or empty sometimes. How can I check this in my Java code?

Answer 1

The obvious answer is String1.contains(String2);

It will throw a NullPointerException if String1 is null. I would check that String1 is not null before trying the comparison; the other situations should handle as you would expect.