Implementing Serializable interface

[javaplus]

Please review the code below:

Code:

public class ClassA implements Serializable{
...}

I implemented Serializable interface and wrote methods according to my requirement. I did not implement any method of Serializable interface. I know that when you implement an interface, you have to implement its methods. I can compile my class and no error are shown.

Is this some special behavior of interface?

[wsaryada]

This is called as a marker interface, which is use to mark a class for serialization purposes. By implementing this interface Java know that this class can be serialized.

Yes, you don't need to implement a method when create a class a serializable because the interface itself doesn't define any method. But there are some rules for creating a good serializable class, you can read it here: Implementing Serializable.

[javaplus]

Thanks a dozen for making this clear.
So, is this right to say that "marker interfaces" are those interfaces, that have no method in them.

[wsaryada]

Well, not really I think. It can have methods or fields. For more information see here: Marker interface pattern - Wikipedia, the free encyclopedia

[jaykishan]

It is also known as null interface....but still you may use readObject() and writeObject() method to serialize and deserialize object....