How to sort a String ArrayList using insertion sort method i

How to sort a String ArrayList using insertion sort method into an initially empty list. Do not insert duplicate words. Java Im having trouble understanding how to make a method that takes an arraylist and sorts it this way

Solution

StringInsertionSort.java

import java.util.ArrayList;

public class StringInsertionSort {

  
   public static void main(String[] args) {
       ArrayList<String> list = new ArrayList<String>();
       list.add(\"Suresh\");
       list.add(\"Asnhu\");
       list.add(\"Sekhar\");
       list.add(\"Revathi\");
       list.add(\"Naresh\");
       System.out.println(\"List elements before sort: \"+list);
       insertionSort(list);
       System.out.println(\"List elements after sort: \"+list);
   }
   public static void insertionSort(ArrayList<String> list){
       int n = list.size();
for (int j = 1; j < n; j++) {
String key = list.get(j);
int i = j-1;
while ( (i > -1) && ( list.get(i).compareTo(key) > 0 ) ) {
   list.set(i+1, list.get(i));
i--;
}
list.set(i+1, key);
}
   }

}

Output:

List elements before sort: [Suresh, Asnhu, Sekhar, Revathi, Naresh]
List elements after sort: [Asnhu, Naresh, Revathi, Sekhar, Suresh]