Why implement Serializable on models?

Question

I noticed in Spring-boot a lot of people create models/entities and implement the Serialiazable interface.

public class ModelBase implements Serializable 

I understand what it means to serialize data/classes as it enables you to save the state of a class (if I'm not wrong, to a file for instance).

But I believe this should be done only when necessary, but either way it seems people just tend to implement the interface.

Is there a different reason?

Answer 1

When your models or entities are meant to travel across several JVM's then you might want to consider implementing Serializable interface. You should do this with caution. You should also provide a a valid UUID for the class to be used during Serialization and vice versa.

Sample is

private static final long serialVersionUID = 9178661439383356177L;

And

According to JPA Spec:

If an entity instance is to be passed by value as a detached object (e.g., through a remote interface), the entity class must implement the Serializable interface.

Also

When using serializable values it is possible to remove this redundancy by changing the entity class in two ways:

Make the entity class serializable, so it can be used in place of the value class.

Make the key fields transient, so they are not redundantly stored in the record.

https://docs.oracle.com/cd/E17277_02/html/collections/tutorial/SerializableEntity.html