What is serialization and deserialization in Java?

Serialization: Serialization is the process of converting an object into a stream of bytes. This stream of bytes can be written to a file, sent over a network, or stored in a database. In Java, the Serializable interface is used to mark classes as serializable, indicating that their objects can be serialized. During serialization, the object’s state is converted into a byte stream, including its instance variables and any objects it references. This byte stream can later be deserialized to reconstruct the object.

Deserialization: Deserialization is the reverse process of serialization. It involves converting a stream of bytes back into an object. In Java, the readObject() method of the ObjectInputStream class is used to deserialize an object. During deserialization, the byte stream is read and used to recreate the object’s state, including its instance variables and any objects it references. The result is a new instance of the original object, which can be used as if it had been created through normal instantiation.

Serialization and deserialization are commonly used in scenarios such as saving and loading objects from files, transmitting objects over a network, or caching objects in memory. They provide a convenient way to preserve and transfer the state of objects in Java applications. However, it’s important to note that not all objects can be serialized by default; classes must implement the Serializable interface and handle any special considerations, such as transient fields or custom serialization logic, to ensure successful serialization and deserialization.