I just found out in Java you can declare a field 'static transient' - the compiler doesn't complain. This doesn't seem to be useful in any way since static fields are not serialized, as we all know.
But I wonder, is there actually a case where 'static transient' fields are useful?
Nope - you said it yourself, static fields aren't serialized.
Kinda weird that the compiler lets you do that though.
In most cases, it is not useful. Static fields are indeed not serialized by the default serializer.
However, static transient fields can be detected via reflection. If someone writes its own serializer and he wants to also serialize static fields, then he might take the transient keyword in consideration and skip the serialization of that particular field.
PS: This answer is posted for the sake of completeness, and is based on Peter Lawrey's comment. Credits to him.
来源：https://stackoverflow.com/questions/4565653/java-static-transient-fields