场景 1状态 / 类型定义// 订单状态枚举publicenumOrderStatus{UNPAID(0,待支付),PAID(1,已支付),DELIVERED(2,已发货),FINISHED(3,已完成),CANCEL(4,已取消);privatefinalintcode;privatefinalStringdesc;OrderStatus(intcode,Stringdesc){this.codecode;this.descdesc;}// getterpublicintgetCode(){returncode;}publicStringgetDesc(){returndesc;}}优势杜绝硬编码数字0/1/2可读性强传入不存在的状态会直接编译报错提前拦截 bug场景 2策略模式publicenumPayStrategy{// 每个枚举绑定独立业务逻辑ALIPAY{Overridepublicvoidpay(Longmoney){System.out.println(支付宝支付money);}},WECHAT{Overridepublicvoidpay(Longmoney){System.out.println(微信支付money);}},CREDIT{Overridepublicvoidpay(Longmoney){System.out.println(银行卡支付money);}};// 抽象策略方法publicabstractvoidpay(Longmoney);}// 调用publicclassTest{publicstaticvoidmain(String[]args){PayStrategy.ALIPAY.pay(999L);PayStrategy.WECHAT.pay(299L);}}场景 3统一返回码全局响应码publicenumResultCode{SUCCESS(200,操作成功),FAIL(500,服务器异常),PARAM_ERROR(400,参数非法),UNAUTHORIZED(401,未登录),FORBIDDEN(403,权限不足);privatefinalIntegercode;privatefinalStringmsg;ResultCode(Integercode,Stringmsg){this.codecode;this.msgmsg;}// getterpublicIntegergetCode(){returncode;}publicStringgetMsg(){returnmsg;}}接口返回// 统一返回实体classResultT{privateIntegercode;privateStringmsg;privateTdata;// 快速成功返回publicstaticTResultTsuccess(Tdata){ResultTresnewResult();res.setCode(ResultCode.SUCCESS.getCode());res.setMsg(ResultCode.SUCCESS.getMsg());res.setData(data);returnres;}}优势全局统一错误码前后端不用反复协商文案修改提示信息仅改枚举一处。