java - 如何按已合并的 2 个列表的 id 对元素进行排序？

Question

我已经合并了上面的列表，但需要根据 id 参数对其进行排序。我该如何以最简单且最佳的方式做到这一点？ 我最初合并了一组 2 个用户，现在我想根据他们的 ID 对他们进行排序，然后显示结果。有任何想法吗？

  import java.io.*;
    import java.util.*;


/*
 * To execute Java, please define "static void main" on a class
 * named Solution.
 *
 * If you need more classes, simply define them inline.
 */

class Employee {
  public String name;
  public int id;

  Employee(String name, int id) {
    this.name = name;
    this.id = id;
  }


  public String toString() {
    return "<name: " + this.name + ", id: " + this.id + ">";
  }
}

class Person {
  public String name;
  public int id;

  Person(String name, int id) {
    this.name = name;
    this.id = id;
  }

  public String toString() {
    return "<name: " + this.name + ", id: " + this.id + ">";
  }
}


public class Solution {
  public static void main(String[] args) {
    List<Employee> employee = generateEmployees();
    List<Person> persons = generatePersons();


ArrayList<Object> merged = new ArrayList<Object>(employee);
        merged.addAll(person);
        System.out.println("merged:"+merged +"\n");


   for(int i=0;i<users.size();i++){
        if(person.get(i).id<=5){
        System.out.println("UserName:"+person.get(i).name+"\n");
        }
      }
     for(int i=0;i<employee.size();i++){
       if(employee.get(i).id<=5){
        System.out.println("DesignerName:"+employee.get(i).name+"\n");
        }
      }

});

  }

提前致谢! 我在网上查看了几种排序方法，但无法弄清楚哪种方法是最好的使用方法。只想在排序后显示结果

Answer 1

User 和 Designer 必须从同一个类扩展。 (或设计器扩展用户)。
然后创建一个比较器 ( javadoc ) 并使用 merged.sort (myComparator) ( javadoc )

[编辑]

class MyComparator implements Comparator<User> {
    @Override
    public int compare(User o1, User o2) {
        return Integer.compare(o1.id, o2.id);
    }
}


public class User {
    public String name;
    public int id;

    User(String name, int id) {
        this.name = name;
        this.id = id;
    }

    public String toString() {
        return "<name: " + this.name + ", id: " + this.id + ">";
    }

}



public class Designer extends User{
    Designer(String enter code herename, int id) {
        super(name, id);
    }
}


public class Solution {
    public static void main(String[] args) {
        ...

        ArrayList<User> merged = new ArrayList<User>(designers);
        merged.addAll(users);
        merged.sort(new MyComparator());
...
    }
}