Java在方法内更新静态变量

Correctly updating a static field from a non-static method is tricky to get right and could easily lead to bugs if there are multiple class instances and/or multiple threads in play. Ideally, static fields are only updated from synchronized static methods.

This rule raises an issue each time a static field is updated from a non-static method.

从非静态方法正确更新静态字段很难做到正确，如果有多个类实例和/或多个线程在起作用，则很容易导致错误。理想情况下，静态字段仅从同步静态方法更新。

每次从非静态方法更新静态字段时，此规则都会引发一个问题。