Transient variable in Java

by Online Tutorials Library July 22, 2022

Transient variable in Java

A transient variable is a special type of variable which we create by using the transient keyword. It is a special type of variable which have a non-serialized value at the time of serialization. A variable that is initialized by its default value during de-serialization is known as a transient variable.

A transient variable plays an important role in preventing an object from being serialized. We can make any variable transient by using the transient keyword.

Usually, the interviewer asks the difference between the volatile and the transient variable. So, the volatile and the transient variables are both different from each other. The transient keyword is mainly used at the time of serializing an object, while the volatile keyword is related to the visibility of variables that are modified by multiple threads at the time of concurrent programming.

Both the volatile and transient keywords are rarely used by the programmer and not so much popular as compared to public, static or final.

In order to exclude the instance variables from the serialization process, we use the transient keyword. In order to indicate compiler to read the value of the variable from the main memory, we use the volatile keyword.

We can use the volatile keyword with static but cannot use the transient keyword with static.

Let’s take an example of a transient variable and understand how it works in Java:

TransientVariableExample.java

  // import required classes and packages     packagetutorAspire.javacodes;    importjava.io.FileInputStream;  importjava.io.FileOutputStream;  importjava.io.ObjectInputStream;  importjava.io.ObjectOutputStream;  importjava.io.Serializable;    // create TransientVariableExample class to understand the concept of transient variable  public class TransientVariableExample {    // main() method start  public static void main(String args[]) {    Book newBook = new Book(1014, “Java and OOPs”, “RS Aggarwal”, 5);  System.out.println(“Book before serialization: ” + newBook);    // use try-catch block  try {  // create instance of FileOutputStream class for newBook  FileOutputStream stream1 = new FileOutputStream(“newBook.ser”);                // create instance of ObjectOutputStream class   ObjectOutputStream stream2 = new ObjectOutputStream(stream1);  stream2.writeObject(newBook);    stream1.close();  stream2.close();                // show message for successful serialized book  System.out.println(“Book is successfully Serialized “);                // create instance of FileInputStream class for newBook  FileInputStream inputStream1 = new FileInputStream(“newBook.ser”);                // create instance of ObjectInputStream class   ObjectInputStream inputStream2 = new ObjectInputStream(inputStream1);                // read data of book from inputStream2              Book oldBook = (Book) inputStream2.readObject();    inputStream1.close();  inputStream2.close();                // show successful messages  System.out.println(“Book is successfully created from the Serialized data and the book after seriazliation is : ” + oldBook);            } catch (Exception e) {  e.printStackTrace();          }        }      }    // create class Book that implements the Serializable interface and has a transient variable.    class Book implements Serializable{      // declare variables   privateint ISBN;// each book has ISBN number  private String title;// for title of the book  private String author;// for author of the book  private transient int edition = 1; // edition of the book, i.e., transient variable not serialized        // initialize variables using constructor  public Book(intisbn, String ttl, String auth, int edition) {  this.ISBN = isbn;  this.title = ttl;  this.author = auth;  this.edition = edition;      }        @Override  public String toString() {          return “Book” + ” ISBN= ” + ISBN + “, title=” + title + “, author=” + author + “, edition=” + edition + ‘}’;      }    }  

Output:

Transient variable in Java

Next TopicWeb crawler Java

Transient variable in Java

Transient variable in Java

Java program to remove duplicate characters from a string

How to Add a Link in WordPress Text widgets

You may also like