import java.util.*; class Ideone { public static void main (String[] args) { ArrayList houses = new ArrayList(); houses.add("casa 1"); houses.add("casa 2"); houses.add("casa 1"); houses.add("casa 3"); ArrayList aux = new ArrayList(); for (String item : houses) if (!aux.contains(item)) aux.add(item); houses = aux; for (String item : houses) System.out.println(item); } } //https://pt.stackoverflow.com/q/110791/101