Effective java 第2版 - 笔记(01) 单例(Singleton)的枚举(enum)实现

 1 public enum Boss {
 2 
 3     INSTANCE;
 4 
 5     private String name;
 6 
 7     public void doSomeThing() {
 8         System.out.println(name + " is doing something now...");
 9     }
10 
11     public String getName() {
12         return name;
13     }
14 
15     public void setName(String name) {
16         this.name = name;
17     }
18 
19 }

 1     @Test
 2     public void testSingleton() {
 3 
 4         Boss b1 = Boss.INSTANCE;
 5         b1.setName("张三");
 6         b1.doSomeThing();//张三 is doing something now...
 7 
 8         Boss b2 = Boss.INSTANCE;
 9         b2.doSomeThing();//张三 is doing something now...
10 
11         System.out.println(b1.equals(b2));//true
12 
13     }