Class combination Serialization : Object Serialization « File « Java Tutorial

1. Java Tutorial
2. File
3. Object Serialization

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

class ID implements Serializable {
}

class Employee implements Serializable {
  private String name;

  private ID myID;

  Employee(String nm, ID h) {
    name = nm;
    myID = h;
  }

  public String toString() {
    return name + "[" + super.toString() + "], " + myID + "\n";
  }
}

public class MainClass {
  public static void main(String[] args) throws IOException, ClassNotFoundException {
    ID id = new ID();
    List employees = new ArrayList();
    employees.add(new Employee("A", id));
    employees.add(new Employee("B", id));
    employees.add(new Employee("C", id));
    System.out.println("employees: " + employees);
    ByteArrayOutputStream buf1 = new ByteArrayOutputStream();
    ObjectOutputStream o1 = new ObjectOutputStream(buf1);
    o1.writeObject(employees);
    o1.writeObject(employees); 

    ByteArrayOutputStream buf2 = new ByteArrayOutputStream();
    ObjectOutputStream o2 = new ObjectOutputStream(buf2);
    o2.writeObject(employees);

    ObjectInputStream in1 = new ObjectInputStream(new ByteArrayInputStream(buf1.toByteArray()));
    ObjectInputStream in2 = new ObjectInputStream(new ByteArrayInputStream(buf2.toByteArray()));
    List emp1 = (List) in1.readObject(), emp2 = (List) in1.readObject(), emp3 = (List) in2
        .readObject();
    System.out.println("emp1: " + emp1);
    System.out.println("emp2: " + emp2);
    System.out.println("emp3: " + emp3);
  }
}

/*
*/

employees: [A[Employee@126b249], ID@182f0db
, B[Employee@192d342], ID@182f0db
, C[Employee@6b97fd], ID@182f0db
]
emp1: [A[Employee@750159], ID@1abab88
, B[Employee@18a7efd], ID@1abab88
, C[Employee@1971afc], ID@1abab88
]
emp2: [A[Employee@750159], ID@1abab88
, B[Employee@18a7efd], ID@1abab88
, C[Employee@1971afc], ID@1abab88
]
emp3: [A[Employee@16cd7d5], ID@cdedfd
, B[Employee@1c39a2d], ID@cdedfd
, C[Employee@bf2d5e], ID@cdedfd
]