Serialization

Serialization is how Java turns a live object in memory into a stream of bytes you can save to disk or send over a network. Once an object is a byte stream, it can sit in a file for hours and be brought back later as the same object. This lesson covers what serialization is, the Serializable marker, how ObjectOutputStream writes objects, the role of transient and static fields, why serialVersionUID exists, how to customize the write process, the Externalizable alternative, and the limitations that drive teams to JSON or Protocol Buffers instead. We focus only on writing here.