Serializace

package soubory;
 
import java.io.Serializable;
 
public class Pes implements Serializable{
    String jmeno;
    String majitel;
 
    public Pes(String jmeno, String majitel){
        this.jmeno = jmeno;
        this.majitel = majitel;
    }
 
    @Override
    public String toString(){
        return jmeno+"("+majitel+")";
    }
}

package soubory;
 
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
 
public class Main {
 
    public static void main(String[] args) throws ClassNotFoundException {
        try {
            ObjectOutputStream file = new ObjectOutputStream(new FileOutputStream("psi.pes"));
            Pes alik = new Pes("alik", "novak");
            Pes azor = new Pes("azor", "dvorak");
            file.writeInt(2);
            file.writeObject(alik);
            file.writeObject(azor);
            file.close();
 
 
            ObjectInputStream vstup = new ObjectInputStream(new FileInputStream("psi.pes"));
            //ukladat pocet neni potreba, ale par veci se tim zjednodusi
            int pocet = vstup.readInt();
 
            for (int i =0; i<pocet; i++){
                Object o = vstup.readObject();
                if (o instanceof Pes){
                    System.out.println(((Pes)o).jmeno);
                }
                System.out.println(o.getClass().getName());
            }
        } catch (IOException ex) {
            //neco se pokazilo
        }
    }
}