Enum入门

package com.bobo.www.cxf.impl;  
  
public enum Traffic {  
  
    Red(1), Green(2), Yellow(3);//必须最前面  
  
    private int flag = 0;  
  
    private Traffic() {  
        System.out.println("init");  
    }  
  
    private Traffic(int flag) {  
        this.flag = flag;  
    }  
  
    public String toString() {  
        return String.valueOf(flag);  
    };  
  
} 

public class doit {  
    public static void main(String[] args) {  
        Traffic t1 = Traffic.Green;  
        for(Traffic t : Traffic.values()){  
            System.out.println(t);  
        }  
        System.out.println();  
    }  
}