print statements not working in serialization code

[navneet kumarbairwal]

\* print statements not working after the read and write statements..*\


import java.io.*;
class cat
{}

class cat1
{
  public static void main(String aa[])
  {
    cat c=new cat();
    try{
      FileOutputStream f=new FileOutputStream("hello.txt");
      ObjectOutputStream fo=new ObjectOutputStream(f);
      fo.writeObject(c);
      System.out.println("nsdfjsdfjs");
      fo.close();
      System.out.println("close");
    }catch(Exception e){}
    try{
      FileInputStream f1=new FileInputStream("hello.txt");
      ObjectInputStream fo1=new ObjectInputStream(f1);
      c=(cat)fo1.readObject();
      System.out.println(c.toString());
      fo1.close();
    }catch(Exception e){}
  }
}

[Edit - formatting - MB]

[Paul Clapham]

Your problem is here:

catch(Exception e){} 

This says: When an exception is thrown, do nothing.

So when an exception is thrown, you have no way of knowing that happened. Except for the indirect clues, like for example a statement not being executed because the statement before it threw an exception.

Replace that code by this more useful code:

catch(Exception e){
  e.printStackTrace();
} 

[Dan Drillich]

If you want to see the less intimidating error version, you can use -

		    	String st = e.toString();
		    	System.out.println(st);  

It shows -

java.io.NotSerializableException: cat

Regards,
Dan

[Bear Bibeault]

Dan Drillich wrote:If you want to see the less intimidating error version, you can use -

Not recommended. That "intimidating" error message contains useful information.

[Dan Drillich]

Thank you Bear - long time no talk ;-).

The following solves the issue -

     class cat implements Serializable
     {}

Regards,
Dan

[sai jyothi]

Hi Navneet

When ever you are trying to use the streams it is mandatory to implement Serializable interface.It is a marker interface which doesnt have any members in it.When a java class is to be serialized, you should intimate the java compiler in some way that there is a possibility of serializing this java class.


Regards
Jyothi