Why generate long serialVersionUID instead of a simple 1L?

java serialization code-generation serialversionuid
IAdapter picture IAdapter · May 20, 2009 · Viewed 82.3k times · Source

When class implements Serializable in Eclipse, I have two options: add default serialVersionUID(1L) or generated serialVersionUID(3567653491060394677L). I think that first one is cooler, but many times I saw people using the second option. Is there any reason to generate long serialVersionUID?

Answer

Michael Myers picture Michael Myers · May 20, 2009

As far as I can tell, that would be only for compatibility with previous releases. This would only be useful if you neglected to use a serialVersionUID before, and then made a change that you know should be compatible but which causes serialization to break.

See the Java Serialization Spec for more details.

Related questions

What is a serialVersionUID and why should I use it?

Eclipse issues warnings when a serialVersionUID is missing. The serializable class Foo does not declare a static final serialVersionUID field of type long What is serialVersionUID and why is it important? Please show an example where missing serialVersionUID will cause …

Read More
Convert a JSON string to object in Java ME?

Is there a way in Java/J2ME to convert a string, such as: {name:"MyNode", width:200, height:100} to an internal Object representation of the same, in one line of code? Because the current method is too tedious: Object n = …

Read More
Java Serializable Object to Byte Array

Let's say I have a serializable class AppMessage. I would like to transmit it as byte[] over sockets to another machine where it is rebuilt from the bytes received. How could I achieve this?

Read More