一文教你正确的在java中使用枚举

package com.ljq.test;public class TestEnum {    public enum ColorEnum {    red, green, yellow, blue;  }      public enum SeasonEnum {    //注：枚举写在最前面，否则编译出错    spring, summer, autumn, winter;    private final static String position = "test";    public static SeasonEnum getSeason() {      if ("test".equals(position))        return spring;      else        return winter;    }  }      public enum Gender{    //通过括号赋值,而且必须带有一个参构造器和一个属性跟方法，否则编译出错    //赋值必须都赋值或都不赋值，不能一部分赋值一部分不赋值；如果不赋值则不能写构造器，赋值编译也出错    MAN("MAN"), WOMEN("WOMEN");        private final String value;    //构造器默认也只能是private, 从而保证构造函数只能在内部使用    Gender(String value) {      this.value = value;    }        public String getValue() {      return value;    }  }      public enum OrderState {        CANCEL {public String getName(){return "已取消";}},        WAITCONFIRM {public String getName(){return "待审核";}},        WAITPAYMENT {public String getName(){return "等待付款";}},        ADMEASUREPRODUCT {public String getName(){return "正在配货";}},        WAITDELIVER {public String getName(){return "等待发货";}},        DELIVERED {public String getName(){return "已发货";}},        RECEIVED {public String getName(){return "已收货";}};        public abstract String getName();  }    public static void main(String[] args) {    //枚举是一种类型，用于定义变量，以限制变量的赋值；赋值时通过“枚举名.值”取得枚举中的值    ColorEnum colorEnum = ColorEnum.blue;    switch (colorEnum) {    case red:      System.out.println("color is red");      break;    case green:      System.out.println("color is green");      break;    case yellow:      System.out.println("color is yellow");      break;    case blue:      System.out.println("color is blue");      break;    }        //遍历枚举    System.out.println("遍历ColorEnum枚举中的值");    for(ColorEnum color : ColorEnum.values()){      System.out.println(color);    }        //获取枚举的个数    System.out.println("ColorEnum枚举中的值有"+ColorEnum.values().length+"个");        //获取枚举的索引位置，默认从0开始    System.out.println(ColorEnum.red.ordinal());//0    System.out.println(ColorEnum.green.ordinal());//1    System.out.println(ColorEnum.yellow.ordinal());//2    System.out.println(ColorEnum.blue.ordinal());//3        //枚举默认实现了java.lang.Comparable接口    System.out.println(ColorEnum.red.compareTo(ColorEnum.green));//-1        //--------------------------    System.out.println("===========");    System.err.println("季节为" + SeasonEnum.getSeason());            //--------------    System.out.println("===========");    for(Gender gender : Gender.values()){      System.out.println(gender.value);    }        //--------------    System.out.println("===========");    for(OrderState order : OrderState.values()){      System.out.println(order.getName());    }  }  }