What does serialVersionUID mean?
The SerialVersionUID can be used during deserialization to verify that the sender and receiver of a serialized object have loaded classes for that object that are compatible w.r.t serialization. If the deserialization object is different than serialization, then it can throw an InvalidClassException.
Can serialVersionUID be anything?
It can be both good and bad – if all you’ve changed is some method body (eg, added null-check) and you’ve not changed / added any field then you don’t really want the serialVersionUID to be different.
How do I find the serialVersionUID of a class?
you can also enable serialization inspection from Settings -> Editor -> Inspections -> enable “Serializable class without ‘serialVersionUID’ check” first, then ALT+ ENTER, the studio will create serialVersionUID for you.
What is serialVersionUID what would happen if you don’t define this?
serialVersionUID is used for version control of object. Consequence of not specifying serialVersionUID is that when you add or modify any field in class then already serialized class will not be able to recover because serialVersionUID generated for new class and for old serialized object will be different.
What is serialVersionUID exception class?
The serialization at runtime associates with each serializable class a version number called a serialVersionUID, which is used during deserialization to verify that the sender and receiver of a serialized object have loaded classes for that object that are compatible with respect to serialization.
When should I update serialVersionUID?
You should change the serialVersionUID only when you deliberately want to break compatibility with all existing serializations, or when your changes to the class are so radical that you have no choice – in which case you should really think several times about what it is that you are actually doing.
Do I need a serialVersionUID?
Simply put, we use the serialVersionUID attribute to remember versions of a Serializable class to verify that a loaded class and the serialized object are compatible. Therefore, it is not necessary for different classes to have unique values.
How serialVersionUID is generated when it’s not defined in code?
If class does not contain a serialVersionUID field, its serialVersionUID will be automatically generated by the compiler. Different compilers, or different versions of the same compiler, will generate potentially different values.
What is the use of serialVersionUID in exception?
Why do we need exception in serialVersionUID?
It’s used for serialization, it should be declared in any class that implements Serializable . It’s effectively a version number the JVM can use to check if a serialized class matches the class definition you’re trying to deserialize it into.
What is a serialVersionUID and why should I use it?
SerialVersionUID is a unique identifier for each class, JVM uses it to compare the versions of the class ensuring that the same class was used during Serialization is loaded during Deserialization. Specifying one gives more control, though JVM does generate one if you don’t specify.
What does serialVersionUID 1L mean?
This is explain here: The serialVersionUID is a universal version identifier for a Serializable class. Deserialization uses this number to ensure that a loaded class corresponds exactly to a serialized object. If no match is found, then an InvalidClassException is thrown.