marker-interfaces

If the Serializable interface is just a Marker-Interface that is used for passing some-sort of meta-data about classes in java - I'm a bit confused: After reading the process of java's serialization algorithm (metadata bottom-to-top, then actual instance data top-to-bottom), I can't really understand what data cannot be processed through that algorithm. In short and formal: What data may cause the NotSerializableException ? How should I know that I am not supposed to add the implements Serializable clause for my class? When you are talking about NotSerializableException it is throw when you

I was being taught that Marker interface in Java is an empty interface and is used to signal to compiler or JVM that the objects of the class implementing this interface must be treated in a special way, like serializing, cloning, etc. But lately I have learned that it actually has nothing to do with the compiler or the JVM. For example, in case of Serializable interface the method writeObject(Object) of ObjectOutputStream does something like instanceOf Serializable to detect whether the class implements Serializable & throws NotSerializableException accordingly. Everything is handled in the