善于使用Java中的枚举

Java中的枚举类似一个简易的小数据库，可以存储一组固定不变的常量，以供其他Java类中的方法调用。如果掌握，可以在很多场景中应用。

以下举一个小例子：

/**
 * 枚举的定义
 * 定义一个“季节”枚举
 */
public enum SeasonEnum{

    ONE(1,"春"),TWO(2,"夏"),THREE(3,"秋"),FOUR(4,"冬");

    private Integer retCode;
    private String retMessage;

    public Integer getRetCode() {
        return retCode;
    }

    public String getRetMessage() {
        return retMessage;
    }

    SeasonEnum(Integer retCode, String retMessage) {
        this.retCode = retCode;
        this.retMessage = retMessage;
    }

    public static SeasonEnum forEach_SeasonEnum(int index){
        SeasonEnum[] myArray = SeasonEnum.values();
        for(SeasonEnum season : myArray){
            if(index == season.getRetCode()){
                return season;
            }
        }
        return null;
    }
}

测试类

public class Test {
    public static void main(String[] args) {
        //枚举的调用
        for(int i=0;i<4;i++){
            System.out.print(SeasonEnum.forEach_SeasonEnum(i+1).getRetMessage());
        }
        System.out.println();
        System.out.println(SeasonEnum.ONE);
        System.out.println(SeasonEnum.ONE.getRetCode());
        System.out.println(SeasonEnum.ONE.getRetMessage());
    }
}

 运行结果展示