Some serialization confusions........please help

Question

confusion 1:
import java.io.*;
public class SerializeDog {
public static void main(String[] args) {
Collar c = new Collar(3);
Dog d = new Dog(c, 5);
System.out.println("before: collar size is "+ d.getCollar().getCollarSize());
try {
FileOutputStream fs = new FileOutputStream("testSer.ser");
ObjectOutputStream os = new ObjectOutputStream(fs);
os.writeObject(d);
os.close();
} catch (Exception e) { e.printStackTrace(); }
try {
FileInputStream fis = new FileInputStream("testSer.ser");
ObjectInputStream ois = new ObjectInputStream(fis);
d = (Dog) ois.readObject();
ois.close();
} catch (Exception e) { e.printStackTrace(); }
System.out.println("after: collar size is "+ d.getCollar().getCollarSize());
class Dog implements Serializable {
private Collar theCollar;
private int dogSize;
public Dog(Collar collar, int size) {
theCollar = collar;
dogSize = size;
public Collar getCollar() { return theCollar; }
class Collar implements Serializable {
private int collarSize;
public Collar(int size) { collarSize = size; }
public int getCollarSize() { return collarSize; }
//output is before 3,after 3In the example above dog use instance variable of type collar which when is not serialized throws notserialized exception. So how do we serialize classes we don?t have access to coding for e.g. if here we did?nt have access to collar class.
confusion 2:
import java.io.*;
class SuperNotSerial {
public static void main(String [] args) {
Dog d = new Dog(35, "Fido");
System.out.println("before: " + d.name + " "+ d.weight);
try {
FileOutputStream fs = new FileOutputStream("testSer.ser");
ObjectOutputStream os = new ObjectOutputStream(fs);
os.writeObject(d);
os.close();
} catch (Exception e) { e.printStackTrace(); }
try {
FileInputStream fis = new FileInputStream("testSer.ser");
ObjectInputStream ois = new ObjectInputStream(fis);
d = (Dog) ois.readObject();
ois.close();
} catch (Exception e) { e.printStackTrace(); }
System.out.println("after: " + d.name + " "
+ d.weight);
class Dog extends Animal implements Serializable {
String name;
Dog(int w, String n) {
weight = w; // inherited
name = n; // not inherited
class Animal { // not serializable !
int weight = 42;
//output
before: Fido 35
after: Fido 42And in this example animal is not serialized so it takes default values when it desrialized for animal instance variable. So how the actual state of object gets saved at all?
Only the current serialized object has its state saved not its perant nor any other classes. So in actual programming wouldn?t it become difficult to serialze and desiralize as even a simple program can have n type of objects not related by inheritance.

Answer 1

confusion 1:
package Basics1;
import java.io.*;
public class SerializeDog {
    public static void main(String[] args) {
        Collar c = new Collar(3);
        Dog d = new Dog(c, 5);
        System.out.println("before: collar size is "+ d.getCollar().getCollarSize());
        try {
            FileOutputStream fs = new FileOutputStream("testSer.ser");
            ObjectOutputStream os = new ObjectOutputStream(fs);
            os.writeObject(d);
            os.close();
            } catch (Exception e) { e.printStackTrace(); }
        try {
            FileInputStream fis = new FileInputStream("testSer.ser");
            ObjectInputStream ois = new ObjectInputStream(fis);
            d = (Dog) ois.readObject();
            ois.close();
            } catch (Exception e) { e.printStackTrace(); }
        System.out.println("after: collar size is "+ d.getCollar().getCollarSize());
class Dog implements Serializable {
    private Collar theCollar;
    private int dogSize;
    public Dog(Collar collar, int size) {
        theCollar = collar;
        dogSize = size;
    public Collar getCollar() { return theCollar; }
class Collar implements Serializable {
    private int collarSize;
    public Collar(int size) { collarSize = size; }
    public int getCollarSize() { return collarSize; }
}In the example above dog use instance variable of type collar which when is not serialized throws notserialized exception. So how do we serialize classes we don?t have access to coding for e.g. if here we did?nt have access to collar class.
package Basics1;
import java.io.*;
class SuperNotSerial {
    public static void main(String [] args) {
        Dog d = new Dog(35, "Fido");
        System.out.println("before: " + d.name + " "+ d.weight);
        try {
            FileOutputStream fs = new FileOutputStream("testSer.ser");
            ObjectOutputStream os = new ObjectOutputStream(fs);
            os.writeObject(d);
            os.close();
            } catch (Exception e) { e.printStackTrace(); }
        try {
            FileInputStream fis = new FileInputStream("testSer.ser");
            ObjectInputStream ois = new ObjectInputStream(fis);
            d = (Dog) ois.readObject();
            ois.close();
            } catch (Exception e) { e.printStackTrace(); }
            System.out.println("after: " + d.name + " "+ d.weight);
class Dog extends Animal implements Serializable{
    String name;
    Dog(int w, String n) {
        weight = w; // inherited
        name = n; // not inherited
class Animal { // not serializable !
    int weight = 42;
}And in this example animal is not serialized so it takes default values when it desrialized for animal instance variable. So how the actual state of object gets saved at all?
Only the current serialized object has its state saved not its perant nor any other classes. So in actual programming wouldn?t it become difficult to serialze and desiralize as even a simple program can have n type of objects not related by inheritance.
i think it is pretty formated now