List<String> strs = Arrays.asList("a", "a", "a", "a", "b");

        boolean aa = strs.stream().anyMatch(str -> str.equals("a"));//只要有一个满足返回true

        boolean bb = strs.stream().allMatch(str -> str.equals("a"));//所有都要满足返回true

        boolean cc = strs.stream().noneMatch(str -> str.equals("a"));//所有都不满足返回true

        long count = strs.stream().filter(str -> str.equals("a")).count();//过滤满足'a'的个数

        System.out.println(aa);// TRUE

        System.out.println(bb);// FALSE

        System.out.println(cc);// FALSE

        System.out.println(count);//

List<Integer> list1 = new arrayList<>();

list1.add(1);

list1.add(2);

list1.add(3);

list1.add(4);

list1.add(5);

list1.add(6);

List<Integer> filterList1 = list1.stream().filter(s->s>=1 && s<=3).collect(Collectors.toList());

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

list.add(10);

list.add(10);

list.add(20);

List<Integer> filterList = list.stream().distinct().collect(Collectors.toList());