about serialization

[karnatam narendraprasad]

import java.io.*;
 
class Dog implements Serializable{
private transient Collar theCollar;
private int dogSize;
public Dog(Collar collar,int size){
theCollar=collar;
dogSize=size;
}
public Collar getCollar(){return theCollar;}
}
 
class Collar {
private int collarSize;
public Collar(int size){ collarSize=size;}
public int getCollarSize(){ return collarSize;}
}
 
 
class SerializeDog1{
public static void main(String []args){
Collar c=new Collar(3);
Dog d=new Dog(c,8);
System.out.println("before :collar size is "+d.getCollar().getCollarSize());
try{
FileOutputStream fs=new FileOutputStream("Testser.ser");
ObjectOutputStream os=new ObjectOutputStream(fs);
os.writeObject(c);
os.close();
}
catch(Exception e){}
try{
FileInputStream fs=new FileInputStream("Testser.ser");
ObjectInputStream ois=new ObjectInputStream(fs);
d=(Dog)ois.readObject();
ois.close();
}
catch(Exception e){}
System.out.println("after :collar size is "+d.getCollar().getCollarSize());
 
}
}

in the above collar is not serilazed. but the program excutes fine .what is the use of "transient"


EDIT by mw: Added Code Tags -- please use these when posting code.
[ March 16, 2007: Message edited by: marc weber ]

[marc weber]

Originally posted by karnatam narendraprasad:
...in the above collar is not serilazed. but the program excutes fine .what is the use of "transient"

JLS - 8.3.1.3 transient Fields: "Variables may be marked transient to indicate that they are not part of the persistent state of an object."

It might look like your program "executes fine," but it's not really doing what you think it's doing. It's a bad habit to catch an exception and do nothing with it -- for example...

catch(Exception e){}

If you add System.err.println(e); to your catch blocks, you should see what's really happening here.
[ March 16, 2007: Message edited by: marc weber ]