package com.bytezero.test2;
 2 
 3 public class Person
 4 {
 5     private int age;
 6      
 7     public void setAge(int a)
 8     {
 9         if(a <=0 || a> 130)
10         {
11             //throw new RuntimeException("传入的数据非法！！");
12             System.out.println("传入的数据非法！！");
13             
14             //return;   1:
15         }
16     
17             //age = a;  1:
18         
19         else
20         {
21             age = a;
22         }
23     }
24     
25     public int getAge()
26     {
27         return  age;
28     
29         
30     }
31     
32     //不行
33 //    public int doAge(int a)
34 //    {
35 //        age =a;
36 //        return age;
37 //    }
38     
39     
40     
41     
42     
43     
44     
45 }

 1 package com.bytezero.test2;
 2 
 3 public class PersonTest 
 4 {
 5     public static void main(String[] args)
 6     {
 7         
 8         Person p1 = new Person();
 9         
10         //p1.age = 1;    //已经私有化  不能调用
11         
12         //p1.setAge(-12);  //传入的数据非法！！
13         
14         p1.setAge(12);
15         int age= p1.getAge();  
16         System.out.println(age); //12
17         
18         System.err.println("年龄为："+p1.getAge());  //年龄为：12
19         
20     
21     }  
22 }