1) You can't create a new Object and then cast it to a String. You will receive a ClassCastException because an Object is not a String (but a String is an Object). Just create a new String instead.
2) You executed the query but never traverse the ResultSet. Depending on the maximum number of results you expect (1 or more than 1), you need an if statement or loop:
Note that if you use a loop you should use a List<String> to store your data. Remember to create the new String inside the loop, otherwise you will have only one single String object and change that for each record.
3) Although array indexing is 0-based, JDBC is 1-based. You need to account for that: