Why does the program hang when creating an ObjectInputStream?

Question

Java

System.out.print("Я здесь"); //выводит
            in = new ObjectInputStream(socket.getInputStream());
            System.out.print("Я здесь1"); //не выводит
            out = new ObjectOutputStream(socket.getOutputStream());
            System.out.print("Я здесь2");

If ObjectInputStream is replaced with DataInputStream everything works fine. What could be the reason?

Answer 1

Docs: https://docs.oracle.com/javase/7/docs/api/java/io/...

This constructor will block until the corresponding ObjectOutputStream has written and flushed the header.