用枚举消除if-else

目录

定义操作

定义枚举

使用方式

---

今天不知道哪位大神保佑,让我突然想起了曾经写过的一段多达十多个的if...else,被自己恶心到了,今天仔细想了想,梳理了一个自己觉得很优雅的化解此局的方法

定义操作

/**
 * @author bemav
 */
@Service
public class CalculateService {
    public Integer add(Integer a,Integer b){
        return a+b;
    }
    public Integer subtract(Integer a,Integer b){
        return a-b;
    }
    public Integer multiply(Integer a,Integer b){
        return a*b;
    }
    public Integer divide(Integer a,Integer b){
        return a/b;
    }
}

 

定义枚举

并且将枚举对应的操作也赋到枚举上

@Getter
public enum OperationEnum {
    ADD("CREATE", SpringApplicationContextHolder.getBean(CalculateService.class)::add),
    SUBSTRACT("DELETE",SpringApplicationContextHolder.getBean(CalculateService.class)::subtract),
    MULTIPLY("DELETE",SpringApplicationContextHolder.getBean(CalculateService.class)::multiply),
    DIVIDE("UPDATE",SpringApplicationContextHolder.getBean(CalculateService.class)::divide),
    TEST("UPDTESTATE",(a,b)->a-b);

    private String operation;
    private BiFunction<Integer,Integer,Integer> biFunction;
    OperationEnum(String operation,BiFunction<Integer,Integer,Integer> biFunction){
        this.operation=operation;
        this.biFunction=biFunction;
    }

    public static OperationEnum getInstance(String operation){
        for (OperationEnum operationEnum: OperationEnum.values()){
            if (operationEnum.getOperation().equals(operation)){
                return operationEnum;
            }
        }
        return null;
    }
}

使用方式

OperationEnum.getInstance("ADD").getBiFunction().apply(3,5);