问题描述

实现思路

问题描述

问题:需要根据对象的某个属性去重，不关心具体留下哪个元素。

[Student(code=1, name=zhangsan, age=10), Student(code=2, name=lisi, age=20), Student(code=1, name=wangwu, age=20)]
[Student(code=1, name=zhangsan, age=10), Student(code=2, name=lisi, age=20)]

实现思路

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.TreeSet;
import java.util.stream.Collectors;

public class Test03 {
    public static void main(String[] args) {
        Student s1 = new Student(1,"zhangsan",10);
        Student s2 = new Student(2,"lisi",20);
        Student s3 = new Student(1,"wangwu",20);
        List<Student> students = new ArrayList<>();
        students.add(s1);
        students.add(s2);
        students.add(s3);
        System.out.println(students);
        List<Student> result = students.stream()
                .collect(Collectors.collectingAndThen(Collectors.toCollection(() -> new TreeSet<>(Comparator.comparing(Student::getCode))), ArrayList::new));
        System.out.println(result);
    }
}

@Data
@NoArgsConstructor
@AllArgsConstructor
class Student {
    private int code;
    private String name;
    private int age;
}