这是一个接口的源码,运行时遇到点奇怪的问题,如下代码,其中红色代码是啥意思,没见过这种写法,请教高手指点:
import java.util.*;

public class EmployeeSortTest {
  public static void main(String[] args) {
    Employee[] staff=new Employee[3];
    staff[0]=new Employee("man1",1000);
    staff[1]=new Employee("b",2000);
    staff[2]=new Employee("c",500);

    Arrays.sort(staff);

    for(Employee e:staff)  
  {
      System.out.println("姓名"+e.getName()+"  薪水="+e.getSalary());
    }
  }
}


class Employee
    implements Comparable {
  private String name;
  private double salary;
  public Employee(String n, double s) {
    String name = n;
    double salay = s;
  }

  public String getName() {
    return name;
  }

  public double getSalary() {
    return salary;
  }

  public void raiseSalary(double byPercent) {
    double raise = salary * byPercent / 100;
    salary += raise;
  }

  public int compareTo(Employee other) {
    if (salary < other.salary)
      return -1;
    if (salary > other.salary)
      return 1;
    return 0;
  }

  public int compareTo(Object o) {
    return 0;
  }
}

运行结果:
姓名null  薪水=0.0
姓名null  薪水=0.0
姓名null  薪水=0.0