Remove Duplicates from Array of Strings

My solution:

1. Create a HashSet for checking duplicates and ArrayList for record results.
2. Traverse the String array from end to begin, in each iteration, we convert every string to lowercase and sort it.
3. If the set doesn't have the sorted string we got from step 2, we add it to the HashSet and add the current string to the ArrayList.
4. Reverse the ArrayList and convert it to the String array for return.

My code is in the following:

import java.util.*;
public class Solution{
public String[] removeDuplicates(String[] input){
    HashSet<String> set = new HashSet<String>();
    ArrayList<String> ret = new ArrayList<String>();
    for(int i = input.length - 1; i >= 0; i--){
        String currString = input[i].toLowerCase();
        char currStringArray[] = currString.toCharArray();
        Arrays.sort(currStringArray);
        String sortedString = Arrays.toString(currStringArray);
        if(!set.contains(sortedString)){
            ret.add(input[i]);
            set.add(sortedString);
        }
    }
    Collections.reverse(ret);
    return ret.toArray(new String[ret.size()]);
}
public static void main(String args[]){
    String[] input = {"apple Orange", "ORANGE apple", "APPLe oRange", "HI There", "THERE hI"};
    Solution s = new Solution();
    String[] result = s.removeDuplicates(input);
    for(String e : result){
        System.out.println(e);
    }
}