Prove this: Serialization Is Not for Statics in java?

Question

Prove this: Serialization Is Not for Statics in java?With an example.

Vulpes · Answer

Consider this simple example: // Animal.java import java.io.*; public class Animal implements Serializable { public static int numberOfAnimals; public String name; public String type; public int age; public Animal(String name String type int age) { this.name = name; this.type = type; this.age = age; numberOfAnimals++; } public String toString() { return Name =  + name +  Type =  + type +  Age =  + age; } public static void main(String[] args) { String filename = animal.ser; Animal a = new Animal(Leo Lion 3); System.out.println(Number of animals before serialization is  + Animal.numberOfAnimals); // serialize the object to file FileOutputStream fos = null; ObjectOutputStream out = null; try { fos = new FileOutputStream(filename); out = new ObjectOutputStream(fos); out.writeObject(a); out.close(); } catch (Exception ex) { ex.printStackTrace(); } // now change the static field Animal.numberOfAnimals = 5; // deserialize the object from file FileInputStream fis = null; ObjectInputStream in = null; try { fis = new FileInputStream(filename); in = new ObjectInputStream(fis); a = (Animal)in.readObject(); in.close(); } catch (Exception ex) { ex.printStackTrace(); } System.out.println(a); System.out.println(Number of animals after deserialization is  + Animal.numberOfAnimals); } } When you compile and run this program the output is: Number of animals before serialization is 1 Name = Leo Type = Lion Age = 3 Number of animals after deserialization is 5 The value of the static field numberOfAnimals has changed from 1 to 5 because we set it to 5 after we'd serialized the object. As the original value of 1 has not been restored this proves that static fields are not serialized.

Abhijeet Singh · Answer

Thank you sir.. :)

Prove this: "Serialization Is Not for Statics" in java?