Java tutorial
import java.util.HashMap; import java.util.Map; import java.util.TreeMap; public class Main { public static void main(String[] args) { Map<String, String> oldMap = new HashMap<String, String>(); oldMap.put("a", "1"); oldMap.put("A", "2"); Map<String, String> newMap = new TreeMap<String, String>(String.CASE_INSENSITIVE_ORDER); newMap.putAll(oldMap); String value = newMap.get("a"); System.out.println(value); } }