Here is an example that prompts the user to enter two strings in order to check whether they are permutation of each other or not.

class CheckPermutation{
    public static boolean isPermutation(String st1, String st2) {
        if (st1.length() != st2.length()) {
            return false;
        }

        int[] count = new int[256];
        for (int i = 0; i < st1.length(); ++i) {
            ++count[st1.charAt(i)];
        }

        for (int i = 0; i < st2.length(); ++i) {
            if (--count[st2.charAt(i)] < 0) {
                return false;
            }
        }
        return true;
    }

    public static void main(String[] args) 
    {
        String st1="abcd";
        String st2="bacd";
        if(isPermutation(st1,st2)){
            System.out.println("Strings are permutations of each other.");
        }
        else{
            System.out.println("Strings are not permutations of each other.");
        }
    }
}