Java SerialVersionUID: Understanding Class Versioning for Serialization

serialVersionUID is a unique identifier for a Java serializable class. It's used to identify the version of the class during the serialization and deserialization process. When a serialized object is received, the serialVersionUID is used to check if the class versions match. If the versions don't match, an InvalidClassException is thrown.

The serialVersionUID is a static final long field that is automatically generated by the Java compiler when a class is compiled. It's based on the class's implementation details, such as its fields, methods, and inheritance hierarchy. If a class is modified in a way that affects its serialization behavior, such as changing its fields or adding new methods, the serialVersionUID should be updated to reflect the changes.

In summary, serialVersionUID is a mechanism to ensure that the serialized and deserialized objects are compatible with each other, by checking the version of the class.