当我创建一个字符串时java.lang.ArrayIndexOutOfBoundsException

Ok so I'm trying to generate a random character generator that goes beyond simple numbers and letters. I want to simultaneously create a replica of that same generator for the purpose of comparing them and having it print out how many attempts it took for "Cracker" to match the value of "Generator" because I'm interested in the concept after reading a bit of cryptography. When parsing the characters to a string, I get an OutOfBoundsException, but why? I can't seem to find much on the limitations of string. I would think it would have to been an issue besides the string not being able to take the characters but I can't figure it out.Ok so I'm trying to generate a random character