How to check for key in a Map irrespective of the case? [duplicate]

Answer 1

Use a TreeMap which is constructed with String#CASE_INSENSITIVE_ORDER.

Map map = new TreeMap(String.CASE_INSENSITIVE_ORDER);
map.put("FOO", "FOO");

System.out.println(map.get("foo")); // FOO
System.out.println(map.get("Foo")); // FOO
System.out.println(map.get("FOO")); // FOO