基于类的访问权限

 1 public class Stringtest {
 2     public static void main(String[] args){
 3         Employee employee=new Employee("hehe");
 4         Employee boss=new Employee("boss");
 5         System.out.println(employee.equals(boss));
 6         
 7         }
 8     }
 9 class Employee{
10     private String name;
11     public String getName(){
12         return name;
13     }
14     public void setName(String name){
15         this.name=name;
16     }
17     Employee(String name){
18         this.name=name;
19     }
20     public boolean equals(Employee other){
21         return name.equals(other.name);
22     }
23 }

equals方法访问了employee的私有域，也访问了boss的私有域。这是合法的，缘由是boss是Employee对象，而Employee类的方法能够访问Employee类的任何一个对象的私有域