連休だしJavaコレクションの歴史を振り返ってみる ref: http://qiita.com/tag1216/items/3f222ae3cae88210f769

Comparatorのメソッドを使ってソート

        persons.sort(Comparator.comparing(
                Person::getLastName, Comparator.reverseOrder()));

file0.java

        Vector list = new Vector();
        list.add(new Integer(9));
        list.add(new Integer(3));
        list.add(new Integer(4));

        Enumeration e = list.elements();
        while (e.hasMoreElements()) {
            Integer val = (Integer) e.nextElement();
            System.out.println(val);
        }

        for (int i = 0; i < list.size(); i++) {
            System.out.println(list.elementAt(i));
        }

file1.java

        List list = new ArrayList();
        list.add(new Integer(9));
        list.add(new Integer(3));
        list.add(new Integer(4));

        Iterator itr = list.iterator();
        while (itr.hasNext()) {
            Integer val = (Integer) itr.next();
            System.out.println(val);
        }

        for (int i = 0; i < list.size(); i++) {
            System.out.println(list.get(i));
        }

file2.java

        Collections.sort(list, new Comparator() {
            public int compare(Object o1, Object o2) {
                return ((Integer) o1).compareTo((Integer) o2);
            }
        });

file3.java

        List<Integer> list = new ArrayList<Integer>();
        list.add(9);
        list.add(3);
        list.add(4);
        for (int val : list) {
            System.out.println(val);
        }

file4.java

        List<Integer> list = Arrays.asList(9, 3, 4);

file5.java

        List<Integer> list = new ArrayList<>();

StreamAPI

        IntStream.rangeClosed(1, 10)
            .filter(x -> x % 3 == 0)
            .map(x -> x * 2)
            .sum();

ソート

        list.sort((x, y) -> {return x - y;});

メソッド参照

        List<Integer> list = Arrays.asList(9, 3, 4);
        list.forEach(System.out::println);

ラムダ式

        List<Integer> list = Arrays.asList(9, 3, 4);
        list.forEach(val -> System.out.println(val));