Java 封装性的四种权限测试 + 总结

*    总结封装性：Java提供了4中权限修饰符来修饰类及类的内部结构，体现类及类的内部结构
再被调用时的可见性的大小

 1 package com.bytezero.circle;
 2
 3 public class Order
 4 {
 5     private int orderPrivate;
 6     int orderDefault;
 7
 8     public int orderPublic;
 9
10     private void methodPrivate()
11     {
12         orderPrivate = 1;
13         orderDefault = 2;
14         orderPublic = 3;
15     }
16
17      void methodDefault()
18     {
19         orderPrivate = 1;
20         orderDefault = 2;
21         orderPublic = 3;
22     }
23
24     public void methodPublic()
25     {
26         orderPrivate = 1;
27         orderDefault = 2;
28         orderPublic = 3;
29     }

 1 package com.bytezero.circle;
 2
 3 public class OrderTest
 4 {
 5     public static void main(String[] args)
 6     {
 7         Order order = new Order();
 8
 9         order.orderDefault = 1;
10         order.orderPublic = 2;
11
12         //出了Order类之后，私有结构就不可以调用
13         //order.orderPrivate = 3; //The field Order.orderPrivate is not visible
14
15
16         order.methodDefault();
17         order.methodPublic();
18
19
20         //出了Order类之后，私有结构就不可以调用
21         //order.methodPrivate();
22
23
24     }
25 }

 1 package com.bytezero.circle2;
 2
 3 import com.bytezero.circle.Order;
 4
 5 public class OrderTest2
 6 {
 7     public static void main(String[] args)
 8     {
 9         Order order = new Order();
10
11         order.orderPublic = 2;
12
13         //出了Order类所属的包之后，私有结构，缺省就不可以调用
14         //order.orderDefault = 1;
15         //order.orderPrivate = 3; //The field Order.orderPrivate is not visible
16
17         //出了Order类所属的包之后，私有结构，缺省就不可以调用
18         //order.methodDefault();
19
20         order.methodPublic();
21
22
23         //出了Order类之后，私有结构就不可以调用
24         //order.methodPrivate();
25     }
26 }