1.去重复,返回List集合

public class TestStream {
@Test
void test01() {
    People p = new People(1, "北京");
    People p1 = new People(1, "北京");
    People p2 = new People(1, "上海");
    People p3 = new People(1, "天津");
    People p4 = new People(2, "武汉");
    People p5 = new People(2, "天津");
    People p6 = new People(2, "武汉");
    People p7 = new People(2, "合肥");
    List<People> people = Arrays.asList(p, p1, p2, p3, p4, p5, p6, p7);
    // 去重
    ArrayList<People> result = people.stream().collect(collectingAndThen(
            toCollection(
                    () -> new TreeSet<>(Comparator.comparing(l->l.getId()+"-"+l.getAddress()))

            ), ArrayList::new

            )
    );
    result.forEach(s-> System.out.println(s));
}

}

@Data
@AllArgsConstructor
@NoArgsConstructor
class People {
	private int id;
	private String address;
}

Stream