“静态是邪恶的”这个问题更多的是关于全局状态的问题。一个变量保持静态的适当时间是当它从来没有超过一个状态时;IE工具应该可以被整个框架访问，并且总是为相同的方法调用返回相同的结果，这些都不是静态的“邪恶”。关于你的评论:

我发现静态变量使用起来更方便。我认为他们也很有效率

对于永远不会改变的变量/类，静态是理想和有效的选择。

The problem with global state is the inherent inconsistency that it can create. Documentation about unit tests often address this issue, since any time there is a global state that can be accessed by more than multiple unrelated objects, your unit tests will be incomplete, and not 'unit' grained. As mentioned in this article about global state and singletons, if object A and B are unrelated (as in one is not expressly given reference to another), then A should not be able to affect the state of B.

在良好的代码中，有一些禁用全局状态的例外，例如时钟。时间是全局的，在某种意义上，它改变了对象的状态，而不需要编码关系。

不。全球国家本身并不邪恶。但我们必须看看你的代码，看看你是否正确使用了它。一个新手很有可能滥用全局状态;就像他会滥用每一种语言特性一样。

全局状态是绝对必要的。我们不能回避全球国家。我们无法避免对全球状态进行推理。-如果我们关心我们的应用程序语义。

那些为了摆脱全局状态而试图摆脱全局状态的人，最终不可避免地会得到一个更复杂的系统——全局状态仍然存在，巧妙地/愚蠢地伪装在许多层间接之下;在解开所有的间接之后，我们仍然需要推理全局状态。

就像Spring的人在xml中大量声明全局状态，并认为它在某种程度上更优越。

@Jon Skeet如果我创建一个对象的新实例，现在你有两件事要考虑——对象内部的状态，以及承载对象的环境的状态。

总结在Java中使用静态方法的几个基本优点和缺点:

优点:

全局可访问，即不与任何特定的对象实例绑定。 每个JVM一个实例。 可以通过类名访问(不需要对象)。 包含一个适用于所有实例的值。 在JVM启动时加载，并在JVM关闭时死亡。 它们不会修改Object的状态。

缺点:

Static members are always part of memory whether they are in use or not. You can not control creation and destruction of static variable. Usefully they have been created at program loading and destroyed when program unload (or when JVM shuts down). You can make statics thread safe using synchronize but you need some extra efforts. If one thread change value of a static variable that can possibly break functionality of other threads. You must know “static“ before using it. You cannot override static methods. Serialization doesn't work well with them. They don't participate in runtime polymorphism. There is a memory issue (to some extent but not much I guess) if a large number of static variables/methods are used. Because they will not be Garbage Collected until program ends. Static methods are hard to test too.

从我的观点来看，静态变量应该只读取数据或变量创建的约定。

For example we have a ui of some project, and we have a list of countries, languages, user roles, etc. And we have class to organize this data. we absolutely sure that app will not work without this lists. so the first that we do on app init is checking this list for updates and getting this list from api (if needed). So we agree that this data is "always" present in app. It is practically read only data so we don't need to take care of it's state - thinking about this case we really don't want to have a lot of instances of those data - this case looks a perfect candidate to be static.

这里有很多很好的答案，

记忆: 静态变量只要类加载器存在(通常直到VM死亡)就存在，但这只是在大块对象/引用存储为静态的情况下。

模块化: 考虑IOC、依赖注入、代理等概念。所有这些都完全反对紧密耦合/静态实现。

其他缺点:线程安全性，可测试性

以上所有答案都说明了为什么静态方法很糟糕。它们是邪恶的原因是因为它给人一种错误的印象，即你在编写面向对象的代码，而事实上你并不是。 这简直是邪恶。