Java枚举类型实现构造方法、抽象方法

package org.local;
public class Test {
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.println(weekday.A);
		
		System.out.println(TrafficLamp.YELLOW.nextLamp());
	}
	
	public enum weekday{
		A(1),B,C,D,E,F,G;
		
		private weekday(){}//实现私有构造方法
		private weekday(int day){
			System.out.println(day);
		}
	}
	
	public enum TrafficLamp{
		RED {//内部匿名子类
			@Override
			public TrafficLamp nextLamp() {
				// TODO Auto-generated method stub
				return GREEN;
			}
		},
		GREEN {
			@Override
			public TrafficLamp nextLamp() {
				// TODO Auto-generated method stub
				return YELLOW;
			}
		},
		YELLOW {
			@Override
			public TrafficLamp nextLamp() {
				// TODO Auto-generated method stub
				return RED;
			}
		};
		
		public abstract TrafficLamp nextLamp();
	}
}