// ex 4

// ex 4c: A java.io,NotSerializableException is thrown when trying to serialize instances of classes which do not implement the Serializable interface

// ex 4d: A NoClassDefFoundError is thrown 

import java.io.*;

public class SerializableTester {
	
	public static void main(String[] args) throws IOException, ClassNotFoundException {
		Person p1 = new Person("Hans");
		Person p2 = new Person("Palle");
		Car c1 = new Car("green", p1); 
		Car c2 = new Car("red", p2); 

		// ex a		
		ObjectOutputStream oos = new ObjectOutputStream( new FileOutputStream("tmp") );
		oos.writeObject(p1);
		oos.writeObject(p2);
		oos.close();
		
		// print the persons and their cars
		ObjectInputStream ois = new ObjectInputStream( new FileInputStream("tmp") );
		p1 = (Person) ois.readObject();
		p2 = (Person) ois.readObject();
		System.out.println(p1);
		System.out.println(p2);
		ois.close();
		
		// ex b 
		// change one of the objects 
		new Car("purple", p1); // hans now has a new car
		
		// save and load the objects again
		oos = new ObjectOutputStream( new FileOutputStream("tmp2") );
		oos.writeObject(p1);
		oos.writeObject(p2);
		oos.close();
		ois = new ObjectInputStream( new FileInputStream("tmp2") );
		System.out.println( ois.readObject() );
		System.out.println( ois.readObject() );
		ois.close();
	}
}


class Car implements Serializable {
	Person owner;
	String color;
	Car(String color, Person owner) {
		this.owner = owner;
		this.color = color;
		owner.setCar(this);
	}
	
	public String toString() { 
		return color + " car";
	}
}

class Person implements Serializable {
	String name;
	Car car;
	Person(String name) {
		this.name = name;
	}
	
	void setCar(Car car) {
		this.car = car;
	}
	
	public String toString() { 
		return name +"'s " + car;
	}
}