lambda表达式使用案例

public class test {    public static void main(String[] args) {        List<Persona> list = new ArrayList<>();        list.add(new Person("test",1L));        list.add(new Person("tes2t",3L));        final Long[] total = {0L};        list.forEach(person -> {            total[0] = total[0] + person.getAmount();        });        System.out.println(total[0]);    }}

public class Person{    private String name;    private Long amount;}