【Java】【7】枚举类

用处：规范了参数的形式，更简洁易懂

实例：

//消息类型
public enum MessageTypeEnum {
    AdminReward(1, "官方消息"),
    StoreReward(2, "答题奖励"),
    QuarterReward(3, "季度获奖"),
    YearReward(4, "年度获奖");

    private int index;
    private String name;

    private MessageTypeEnum(int index, String name) {
        this.index = index;
        this.name = name;
    }

    public int getIndex() {
        return index;
    }

    public void setIndex(int index) {
        this.index = index;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public static String getName(int index) {
        for (MessageTypeEnum item : MessageTypeEnum.values()) {
            if (item.getIndex() == index) {
                return item.getName();
            }
        }
        return "";
    }

}

在代码中的应用

//根据情况给int类型的字段复值
info.setType(MessageTypeEnum.AdminReward.getIndex()); //避免了1,2,3这种魔鬼数字

//根据int的值，获得对应String类型的值
int type = 1；
String name = MessageTypeEnum.getName(type);

//转成list
public List<MessageVo> getPositionList() {
    List<MessageVo> list = new ArrayList<MessageVo>();
    for (MessageTypeEnum item : MessageTypeEnum.values()) {
        MessageVo info = new MessageVo();
        info.setType(item.getIndex());
        info.setName(item.getName());
        list.add(info);
    }

    return list;
}