Java provides a mechanism, called object serialization where an object
can be represented as a sequence of bytes that includes the object's
data as well as information about the object's type and the types of
data stored in the object.
After a serialized object has been written into a file, it can be read
from the file and deserialized that is, the type information and bytes
that represent the object and its data can be used to recreate the
object in memory.
Classes
ObjectOutputStream and ObjectInputStream are high-level streams that contain the methods for serializing and deserializing an object.
STEP 1:- Create Class that going to Serialize
public class Employee implements java.io.Serializable
{
public String name;
public String address;
public int transient SSN;
public int number;
public void mailCheck()
{
System.out.println("Mailing a check to " + name
+ " " + address);
}
}
Notice that for a class to be serialized successfully, two conditions must be met:
- The class must implement the java.io.Serializable interface.
- All of the fields in the class must be serializable. If a field is not serializable, it must be marked transient.
STEP 2:- Serializing an Object:
import java.io.*;
public class SerializeDemo
{
public static void main(String [] args)
{
Employee e = new Employee();
e.name = "Reyan Ali";
e.address = "Phokka Kuan, Ambehta Peer";
e.SSN = 11122333;
e.number = 101;
try
{
FileOutputStream fileOut = new FileOutputStream("employee.ser");
ObjectOutputStream out = new ObjectOutputStream(fileOut);
out.writeObject(e);
out.close();
fileOut.close();
}catch(IOException i)
{
i.printStackTrace();
}
}
}
STEP 3:- Deserializing an Object:
import java.io.*;
public class DeserializeDemo
{
public static void main(String [] args)
{
Employee e = null;
try
{
FileInputStream fileIn =
new FileInputStream("employee.ser");
ObjectInputStream in = new ObjectInputStream(fileIn);
e = (Employee) in.readObject();
in.close();
fileIn.close();
}catch(IOException i)
{
i.printStackTrace();
return;
}catch(ClassNotFoundException c)
{
System.out.println(.Employee class not found.);
c.printStackTrace();
return;
}
System.out.println("Deserialized Employee...");
System.out.println("Name: " + e.name);
System.out.println("Address: " + e.address);
System.out.println("SSN: " + e.SSN);
System.out.println("Number: " + e.number);
}
}
This would produce following result:
Deserialized Employee...
Name: Reyan Ali
Address:Phokka Kuan, Ambehta Peer
SSN: 0
Number:101
