List 중복제거

List<String> years = new ArrayList<String>();

years.add("2017");

years.add("2016");

years.add("2015");

years.add("2014");

years.add("2013");

years.add("2012");

years.add("2017");

years.add("2016");

years.add("2015");

years.add("2011");

List<String> uniqueYears = new ArrayList<String>(new HashSet<String>(years));

String list = {"1","2","3","1","2"};

list = new HashSet<String>(Arrays.asList(list)).toArray(new String[0]);