java 枚举的常见使用方法

JDK1.5引入了新的类型-枚举，枚举的出现在日常开发中带来了极大的方便。

常用方法一：常量

　　JDK1.5之前我们平时定义系统常量，基本都是用public static final ... 出现枚举以后我们可以讲枚举封装在枚举中。

public enum Color {
    YELLOR,RED,BALCK
}

常用方法二：Switch

public class Test {
    
    public static void main(String[] args) {
        Light color = Light.GREEN;
        System.out.println(change(color));
    }
　　/**
     * 枚举switch
     * 
     * @param color
     * @return
     */
    private static String change(Light color) {
        String remind = null;
        switch (color) {
            case RED:
                color = Light.GREEN;
                remind = "红灯停";
                break;
            case GREEN:
                color = Light.GREEN;
                remind = "绿灯行";
                break;
            case YELLOR:
                color = Light.YELLOR;
                remind = "黄灯亮了等一等";
                break;
            default:
                break;
        }
        return remind;
    }
}

 常用方法三：枚举遍历

enum Light {
    YELLOR, RED, GREEN
}

public class Test {

    public static void main(String[] args) {
        EnumIterator();
    }

    /**
     * 枚举遍历
     */
    private static void EnumIterator() {
        
        for (Light light : Light.values()) {
            if (light.equals(Light.GREEN)) {
                System.out.println("绿灯行");
            } else if (light.equals(Light.RED)) {
                System.out.println("红灯停");
            } else if (light.equals(Light.YELLOR)) {
                System.out.println("黄灯亮了等一等");
            }
        }
    }
}

  常用方法四：枚举类中添加新方法

public enum CountryICON {

    China("中国", "china.icon"), USA("美国", "usa.icon"),;

    private String country;

    private String icon;

    private CountryICON(String country, String icon) {
        this.country = country;
        this.icon = icon;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }
　　//通过输入国家名获取所对应的icon
    public static String getIcon(String country) {
        for (CountryICON countryIcon : CountryICON.values()) {
            if (countryIcon.getCountry().equals(country)) {
                return countryIcon.icon;
            }
        }
        return null;
    }

    public void setIcon(String icon) {
        this.icon = icon;
    }

}