stream流根据集合中的元素的属性进行去重的方法

public class StreamListTest {
    public static void main(String[] args) {
    
        List<Student> studentList = new ArrayList<>();
        studentList.add(new Student("1","zhangsan"));
        studentList.add(new Student("1","zhangsan"));
        studentList.add(new Student("1","赵六"));
        studentList.add(new Student("2","wangwu"));
        studentList.add(new Student("3","超仔"));

        List<Student> collect = studentList.stream().distinct().collect(Collectors.toList());
        collect.forEach(System.out::println);

        System.out.println("-----------------------以下是根据对象中的某个属性进行去重");
        List<Student> students = studentList.stream().collect(
                Collectors.collectingAndThen(Collectors.toCollection(() -> new TreeSet<>(
                        Comparator.comparing(Student::getStuNo))),ArrayList::new));

        students.forEach(System.out::println);

    }
}

输出结果:

Student(stuNo=1, name=zhangsan)
Student(stuNo=1, name=赵六)
Student(stuNo=2, name=wangwu)
Student(stuNo=3, name=超仔)
-----------------------以下是根据对象中的某个属性进行去重
Student(stuNo=1, name=zhangsan)
Student(stuNo=2, name=wangwu)
Student(stuNo=3, name=超仔)

 这里可以看到完美根据学生的stuNo去重,如果只是使用distinct()方法去重的只是相同的元素,第二种方法根据某个属性来去重,完美达成。

实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student {
    private String stuNo;
    private String name;
}

 

posted @ 2022-05-07 18:07  程序员hg  阅读(880)  评论(0编辑  收藏  举报