Запись и чтение объекта в файл

package dvano.homework;
 
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
 
/**
 *
 * @author dvano
 */
public final class SimpleProgram {
 
    private SimpleProgram() {}
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        final Android android1 = new Android(new Vector2F(0.0F, 0.0F), "Mega Android", 3);
        final Android android2 = new Android(new Vector2F(50.0F, 32.45F), "Turbo Android", 81);
 
        try {
            try (final ObjectOutputStream outputStream = new ObjectOutputStream(new FileOutputStream("androids.dat"))) {
                outputStream.writeObject(android1);
                outputStream.writeObject(android2);
            }
 
            try (final ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream("androids.dat"))) {
                final Android loadAndroid1 = (Android) inputStream.readObject();
                final Android loadAndroid2 = (Android) inputStream.readObject();
 
                System.out.println(loadAndroid1.getName() + " " + loadAndroid1.getVersion() + " " + loadAndroid1.getPosition());
                System.out.println(loadAndroid2.getName() + " " + loadAndroid2.getVersion() + " " + loadAndroid2.getPosition());
            }
        } catch (IOException | ClassNotFoundException ex) {
            Logger.getLogger(SimpleProgram.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}

package dvano.homework;
 
import java.io.Serializable;
 
/**
 *
 * @author dvano
 */
public final class Android implements Serializable {
 
    private final Vector2F position;
 
    private final String name;
    private final int version;
 
    public Android(final Vector2F position, final String name, int version) {
        this.position = position;
        this.name = name;
        this.version = version;
    }
 
    public void move(final Vector2F vector) {
        this.position.add(vector);
    }
    
    public Vector2F getPosition() {
        return this.position;
    }
 
    public String getName() {
        return this.name;
    }
 
    public int getVersion() {
        return this.version;
    }
}

package dvano.homework;
 
import java.io.Serializable;
 
/**
 *
 * @author dvano
 */
public final class Vector2F implements Serializable {
 
    private float x;
    private float y;
 
    public Vector2F(float x, float y) {
        this.x = x;
        this.y = y;
    }
 
    public Vector2F add(final Vector2F vector) {
        this.x += vector.x;
        this.y += vector.y;
 
        return this;
    }
 
    @Override
    public String toString() {
        return "[" + this.x + " " + this.y + "]";
    }
 
    public float getX() {
        return this.x;
    }
 
    public float getY() {
        return this.y;
    }
}