Should serialVersionUID be unique for different classes?

Question

class A implements Serializable{
    private static final long serialVersionUID = 5L;
    ...
}

and

class B implements Serializable{
    private static final long serialVersionUID = 6L;
    ...
}

then it is necessary to give unique serialVersionUID to both classes.

So can I assign serialVersionUID = 5L for both classes?

I read following links

Why generate long serialVersionUID instead of a simple 1L?

What is a serialVersionUID and why should I use it?

Answer 1

Yes, you can. Serial versions of different classes are independent and do not interfere each other.

PS
Eclipse even proposes you to set serialVersionID by default value that is 1L .

Answer 2

serialVersionUID is needed to remember versions of the class. It should be same while serializing and deserializing. It is a good programming practice to provide this value rather than JVM assigning one(generally it is hash). It is not necessary for two classes to have unique values.

Answer 3

serialVersionUID can be anything.

But the best practice is to start with the lowest number (for example 0L ) and update it whenever you make a change in class which affects serialization , for example, adding/updating/removing a field, in which case you should increase the version number from 0L to 1L and so on.

Answer 4

SerialVersionUUID is an identifier used by a compiler to serialize/deserialize an object. This id is a private member to the class.

Creating new uuid for every serializable is good to have control over the serialization/deserialization process but it need NOT be unique among different classes.

Answer 5

是的，两个不同的类可能具有相同的serialVersionUID变量。但是更喜欢为每个类使用唯一的一个。还要使用8到10位数的长度而不是1作为值。