stream求集合元素的属性值最值

Person p1 = new Person("张三", new BigDecimal("10.0"));
Person p2 = new Person("李四", new BigDecimal("30.0"));
Person p3 = new Person("王五", new BigDecimal("40.0"));
Person p4 = new Person("赵六", new BigDecimal("10.0"));
Person p5 = new Person("马七", new BigDecimal("40.0"));
List<Person> list = new ArrayList<>();
list.add(p1);
list.add(p2);
list.add(p3);
list.add(p4);
list.add(p5);

// 最小值
Optional<BigDecimal> result = list.stream().map(Person::getSalary).min(BigDecimal::compareTo);
// 最大值
// Optional<BigDecimal> result = list.stream().map(Person::getSalary).max(BigDecimal::compareTo);
/**
 * compareTo
 * int a = bigdemical.compareTo(bigdemical2)
 * a = -1,表示bigdemical小于bigdemical2；
 * a = 0,表示bigdemical等于bigdemical2；
 * a = 1,表示bigdemical大于bigdemical2；
 */
List<Person> collect = list.stream().filter(item -> item.getSalary().compareTo(result.get())==0).collect(Collectors.toList());
System.out.println("获取元素最小值：" + collect);

打印结果：
获取元素最小值：[{name='张三', salary=10.0}, {name='赵六', salary=10.0}]
获取元素最大值：[{name='王五', salary=40.0}, {name='马七', salary=40.0}]