Re: abstract static methods (again)

Eric Sosman <>
Tue, 20 Oct 2009 17:37:33 -0400
Tomas Mikula wrote:

On Tue, 20 Oct 2009 12:12:31 -0700, Daniel Pitts wrote:

Why do you want to enforce a static method to exist in children? I can
think of no good reason for it.

And I also want to enforce constructors. I provided two use-cases.

1. serialization frameworks. It is already required that a Serializable
class has a no-arg constructor. But this is not required at compile time.

     You've said this a couple times, but are you sure it's true?
This class (with no no-arg constructor) appears to serialize and
deserialize just fine:


public class Serial implements Serializable {

     private final int value;

     Serial(int value) {
         this.value = value;

     public static void main(String[] unused)
             throws IOException, ClassNotFoundException
         Serial s1 = new Serial(42);
         System.out.println("serializing: value = " + s1.value);
         ByteArrayOutputStream outb = new ByteArrayOutputStream();
         ObjectOutputStream outo = new ObjectOutputStream(outb);

         ByteArrayInputStream inb =
             new ByteArrayInputStream(outb.toByteArray());
         ObjectInputStream ino = new ObjectInputStream(inb);
         Serial s2 = (Serial) ino.readObject();
         System.out.println("deserialized: value = " + s2.value);
         System.out.println("they are "
                 + (s1 == s2 ? "the same object" : "different objects"));


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