如何检测新值已添加到枚举，并且不在交换机中处理 [英] How to detect a new value was added to an enum and is not handled in a switch

问题描述

我不时地向我的项目中的枚举类型添加一个新值。

From time to time I have to add a new value to a enum type in my project.

public enum Day {
  SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, 
   FILENOTFOUND //this one is new one
}

我想要的是有一个编译时错误每个开关，我有没有处理新的值，像这样： / p>

What I would like is to have a compile time error for every switch I have that is not treating the new value, like this one:

switch (color) {
        case MONDAY: 
        case TUESDAY: 
        case WEDNESDAY: 
        case THURSDAY: 
                    System.out.println("Mondays are bad.");
                     break;

        case FRIDAY: System.out.println("Fridays are better.");
                     break;

        case SATURDAY:
        case SUNDAY: System.out.println("Weekends are best.");
                     break;
    } 

有一个默认值：抛出一些异常不够好，我想它是编译时。

Having a default: that throws some exception is not good enough, I would like it to be compile time.

我不认为这是可能的，但也许有人有一个整洁的技巧...

I don't think this is possible but maybe someone has a neat trick...

我认为Findbugs会有一个规则找到那些，但我只看到了：
Eq：为枚举定义的Covariant equals（）方法（EQ_DONT_DEFINE_EQUALS_FOR_ENUM）

I thought Findbugs would have a rule to find those but I only saw this: Eq: Covariant equals() method defined for enum (EQ_DONT_DEFINE_EQUALS_FOR_ENUM)

编辑：我选择Mark的回复做使用Eclipse，听起来就像我所需要的！我不是在findbugs的专家，所以我可能会错过这样的功能，虽然我不这么认为。

I'm choosing Mark's reply, I do use Eclipse and that sounds just like what I needed! I am not an expert in findbugs at all so I might have missed such functionality, though I don't think so.

推荐答案

Eclipse具有可启用的编译时警告/错误：switch未涵盖的枚举常量。

Eclipse has a compile-time warning/error you can enable: Enum constant not covered on "switch".

在您的专案属性（或一般偏好设定）中，前往 Java Compiler - > 错误/警告，请选中启用项目特定设置。您会在潜在的编程问题下找到警告。默认情况下，它设置为忽略，但您可以将其展开为警告或错误。

From your Project properties (or general preferences), go to Java Compiler->Errors/Warnings , check Enable project specific settings. You'll find the warning under Potential programming problems. It's set to Ignore by default but you can bump it up to Warning or Error.

编辑：我认为这是不必说的，但我想我会说它无论如何：这只适用于如果你在Eclipse中开发或使用它进行你的构建管理。显然，Findbugs或类似的等价物将是真正的答案，因为它超越了IDE，可以集成到构建过程中。

I thought this goes without saying but I suppose I'll say it anyway: this is only applicable if you're developing in Eclipse or using it for your build management. Obviously a Findbugs or similar equivalent would be the "real" answer since it transcends the IDE and can be integrated into the build process.

这篇关于如何检测新值已添加到枚举，并且不在交换机中处理的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！