IO Serializableのシーケンス化と逆シーケンス化、およびカスタムシーケンス化

package IO;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

public class Serializable1
{
	public static void main(String[] args) throws Exception
	{
		Person2 p1 = new Person2(21,"zhangsan",4.33);
		Person2 p2 = new Person2(232,"zhangan",66.33);
		Person2 p3 = new Person2(22,"zhanan",6.33);
		
		FileOutputStream fos = new FileOutputStream("pp.txt");
		
		ObjectOutputStream oos = new ObjectOutputStream(fos);
		
		oos.writeObject(p1);
		oos.writeObject(p2);
		oos.writeObject(p3);
		
		oos.close();
		System.out.println("--------------");
		FileInputStream is = new FileInputStream("pp.txt");
		ObjectInputStream ois = new ObjectInputStream(is);
		
		Person2 p= null;
		for(int i = 0; i <3 ; i++)
		{
			p = (Person2)ois.readObject();
			System.out.println(p.age + "     " +  p.name + "     "+ p.height);
		}
		ois.close();
	}
}
class Person2 implements Serializable
{
	int age;
	 String name;
	double height;
	public Person2(int age,String name,double height)
	{
		this.age = age;
		this.name = name;
		this.height = height;
	}
	
	private void writeObject(java.io.ObjectOutputStream ou)throws IOException  // serializable  
	{
		System.out.println("write object");
		ou.writeInt(age);
		ou.writeUTF(name);
		
		
	}
	private void readObject(java.io.ObjectInputStream in)throws IOException,ClassNotFoundException
	{
		age = in.readInt();
		name = in.readUTF();
		
		
		System.out.println("read Object");
	}
	
	
		
		
	
	
	
	
	


}

java.io.ObjectOutputStream.   java.io.ObjectInputStreamカスタムシーケンス化方法