Java

Java: transient Serialization Example

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Java transient keyword is used in serialization to declare a variable when don’t want to serialize.

Note: Fields declare as static will also not serialize.

Pre-requisite:

For Example: In Employee Class fields age is declared with keyword transient. When you serialize the object of class Employee then values of age will not serialize and time of deserialization initialize with default value as per type.

import java.io.Serializable;
public class Employee implements Serializable{
 int id;
 String name;
//This field will not be serialized
 transient int age;
 public Employee(int id, String name,int age) {
  this.id = id;
  this.name = name;
  this.age=age;
 }
}

See Also:

Serialization Example: with transient keyword

import java.io.FileOutputStream;
import java.io.ObjectOutputStream;

public class SerializationWithTransientExample {

	public static void main(String args[]) throws Exception {
		// creating employee object
		Employee e1 = new Employee(111, "Saurabh", 35);
		// writing object into employee file
		FileOutputStream f = new FileOutputStream("employee.txt");
		ObjectOutputStream out = new ObjectOutputStream(f);
		// Serialize employee object as stream and write in file
		out.writeObject(e1);
		out.flush();

		out.close();
		f.close();
		System.out.println("Employee object Serialize Successfully");
	}

}

Output

Employee object Serialize Successfully

Deserialization Example: with transient keyword

import java.io.FileInputStream;
import java.io.ObjectInputStream;

public class DeserializationWithTransientExample {

	public static void main(String[] args) throws Exception {
		 //Read object stream from file
		  ObjectInputStream in=new ObjectInputStream(new FileInputStream("employee.txt"));
		 //Deserialize object stream to employee object
		  Employee e=(Employee)in.readObject();
		  System.out.println("Employee Detail :");
		  System.out.println("Id :"+e.id+"\nName: "+e.name+"\nAge: "+e.age);
		  in.close();  

	}
}

Output

Employee Detail :
Id :111
Name: Saurabh
Age: 0

As you can see, the printing age of the employee returns 0 as the default value for int type because the value of age was not serialized.