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Oracle Certified Professional: Java SE Developer 1Z0-831 (Java SE 25) · Domain 9: Using the Java I/O API

Serialization: Serializable, transient fields, serialVersionUID

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Last reviewed September 25, 2026 · Leer en español

Serialization converts an object graph into a stream of bytes so it can be saved to a file or sent over a network; deserialization rebuilds the objects from those bytes. In Java, you write with ObjectOutputStream.writeObject(obj) and read with ObjectInputStream.readObject(), which returns Object (so you cast) and can throw ClassNotFoundException as well as IOException.

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