API Contents - SCJP Sun Certified Programmer for Java Platform SE6 - page 305

1. package com.sybex.io;
2.
3. import java.io.*;
4. import java.util.GregorianCalendar;
5.
6. public class DeserializeDemo {
7. public static void main(String [] args) {
8. try {
9. File contactsFile = new File(“mycontacts.ser”);
10. FileInputStream fis =
11. new FileInputStream(contactsFile);
12. ObjectInputStream in = new ObjectInputStream(fis);
13.
14. while(fis.available() > 0) {
15. Object obj = in.readObject();
16. if(obj instanceof Contact2) {
17. Contact2 contact = (Contact2) obj;
18. System.out.println(contact);
19. System.out.println(“city = “
20. + contact.getCity());
21. }
22. }
23.
24. in.close();
25. fis.close();
26. }catch(IOException e) {
27. e.printStackTrace();
28. }catch(ClassNotFoundException c) {
29. c.printStackTrace();
30. }
31. }
32. }
The while loop on line 14 reads in objects from the mycontacts.ser fi le until the stream
is empty. Two objects are in the fi le, so the while loop executes twice. The instanceof
comparison on line 16 is true for both objects and line 18 prints the Contact2 object,
outputting the result of its toString method. I added line 19 to explicitly illustrate that
the city fi eld did not get serialized because it was declared transient . Transient fi elds are
ignored during serialization and initialized to their “zero” value during deserialization,
which for references is null . The output of the DeserializeDemo program is