为阵列和优先级队列获取相同比较器的不同输出

Question

我得到阵列和优先级队列的不同输出，请你告诉我它的原因

import java.util.Arrays;
import java.util.Comparator;
import java.util.PriorityQueue;

public class Employee {

private Long id;
private String name;
private int age;
private int salary;

public Employee(Long id , String name , int age , int salary) {
    this.id = id;
    this.name = name;
    this.age = age;
    this.salary = salary;
}

public Long getId() {
    return id;
}

public String getName() {
    return name;
}

public int getAge() {
    return age;
}

public int getSalary() {
    return salary;
}

public static Comparator<Employee> salaryComparator = new Comparator<Employee>() {
    public int compare(Employee e1 , Employee e2) {
        return e1.getSalary() - e2.getSalary();
    }
};


public static void main(String[] args) {

    PriorityQueue<Employee> pe = new PriorityQueue<>(20, new Comparator<Employee>() {
        public int compare(Employee e1 , Employee e2) {
           return e1.getSalary() - e2.getSalary();
        }
    });

    pe.add(new Employee(1L, "jack", 24, 9));
    pe.add(new Employee(4L, "jill", 40, 12));
    pe.add(new Employee(2L, "jill1", 30, 100));
    pe.add(new Employee(3L, "jack2", 35, 11));

    System.out.println("priority queue " +  pe);


        Employee[] empArr = new Employee[4];
        empArr[0] = new Employee(1L, "jack", 24, 9);
        empArr[1] = new Employee(4L, "jill", 40, 12);
        empArr[2] = new Employee(2L, "jill1", 30, 100);
        empArr[3] = new Employee(3L, "jack2", 35, 11);

        Arrays.sort(empArr, Employee.salaryComparator);

        System.out.println(" array " + Arrays.toString(empArr));

}



@Override
public String toString() {
    return "Employee [id=" + id + ", name=" + name + ", age=" + age + ", salary=" + salary + "]";
}
}

输出：

priority queue [Employee [id=1, name=jack, age=24, salary=9], Employee [id=3, name=jack2, age=35, salary=11], Employee [id=2, name=jill1, age=30, salary=100], Employee [id=4, name=jill, age=40, salary=12]]

 array [Employee [id=1, name=jack, age=24, salary=9], Employee [id=3, name=jack2, age=35, salary=11], Employee [id=4, name=jill, age=40, salary=12], Employee [id=2, name=jill1, age=30, salary=100]]