Stream的去重排序

1.List<Integer>排序

List<Integer> list = new ArrayList<>();
list.add(50);
list.add(25);
list.add(25);
list.add(98);
list.add(32);
List<Integer> collect = list.stream().distinct().sorted().collect(Collectors.toList());
System.out.println("去重正序" + collect);
List<Integer> collect1 = list.stream().distinct().sorted(Comparator.reverseOrder()).collect(Collectors.toList());
System.out.println("去重倒序" + collect1);

打印结果
去重正序[25, 32, 50, 98]
去重倒序[98, 50, 32, 25]

2.List<Person>的元素的属性值去重

Person p1 = new Person("张三", new BigDecimal("50.0"));
Person p2 = new Person("王五", new BigDecimal("25.0"));
Person p3 = new Person("李四", new BigDecimal("68.0"));
Person p4 = new Person("赵六", new BigDecimal("17.0"));
Person p5 = new Person("马八", new BigDecimal("25.0"));
List<Person> list = new ArrayList<>();
list.add(p1);
list.add(p2);
list.add(p3);
list.add(p4);
list.add(p5);
List<Person> result = new LinkedList<>();
for (Person person : list) {
    boolean b = result.stream().anyMatch(p -> p.getSalary().compareTo(person.getSalary())==0);
    if (!b) {
        result.add(person);
    }
}
System.out.println(result);

打印结果：
[{name='张三', salary=50.0}, {name='王五', salary=25.0}, {name='李四', salary=68.0}, {name='赵六', salary=17.0}]