To serialize an object means to convert its state to a byte stream so that the byte stream can be reverted back into a copy of the object. A Java object is serializable if its class or any of its superclasses implements either the java. io.

Is every Java class serializable?

Only Classes That Implement Serializable Can Be Serialized

Similar to the Cloneable interface for Java cloning in serialization, we have one marker interface, Serializable, which works like a flag for the JVM. ... When a class implements the Serializable interface, all its sub-classes are serializable as well.

Are abstract classes serializable?

However, even though most abstract classes don't implement Serializable , they may still need to allow their subclasses to do so, if desired. There are two cases. If the abstract class has no state, then it can simply provide a no-argument constructor to its subclasses.