10+ Fullstack Java Developer Interview Questions and Answers for Freshers

Use a messaging system to share information from receptionist to doctor

• Implement a messaging system using a message broker like RabbitMQ or Apache Kafka

• Create a message queue for receptionist to send messages to the doctor

• Doctor subscribes to the message queue to receive messages from receptionist

• Messages can contain patient information, appointment details, etc.

Languages commonly used in web development include HTML, CSS, and JavaScript.

• HTML is used for creating the structure of web pages

• CSS is used for styling the web pages

• JavaScript is used for adding interactivity to web pages

A cookie is a small piece of data stored on the user's computer by the web browser, used to track user activity and personalize user experience.

• Cookies are used to store user preferences, login information, and shopping cart items.

• They help websites remember users and their preferences, making the browsing experience more personalized.

• Cookies can also be used for tracking user behavior, such as analyzing website traffic and targeting advertisements.

• Cookies can be session-base...read more

Design a schema for a social media platform

• Create tables for users, posts, comments, and likes

• Include foreign keys to link tables together

• Add columns for user information such as name, email, and password

• Include timestamps for when posts and comments were created

• Consider adding a table for hashtags to allow for easy searching

Garbage collector is a program that automatically frees up memory occupied by objects that are no longer in use.

• Garbage collector is a part of Java Virtual Machine (JVM)

• It runs in the background and periodically checks for objects that are no longer in use

• It frees up memory occupied by those objects, making it available for new objects

• Garbage collector helps in preventing memory leaks and improves performance

• Example: If an object is created in a method and the method ends, th...read more

Add 2 lists and sort them

• Combine the two lists into a single list

• Use a sorting algorithm to sort the combined list

• Return the sorted list

An algorithm is a step-by-step procedure or set of rules for solving a problem or accomplishing a task.

• An algorithm is a well-defined computational procedure.

• It consists of a sequence of steps that can be executed in a finite amount of time.

• Algorithms can be represented using pseudocode or flowcharts.

• They are used in various fields like computer science, mathematics, and engineering.

• Examples of algorithms include sorting algorithms (e.g., bubble sort, merge sort) and searchin...read more

A variable is a named storage location in a computer's memory that can hold a value.

• Variables are used to store and manipulate data in a program.

• They have a name, a data type, and a value.

• The value of a variable can be changed during program execution.

• Variables can be used to perform calculations, store user input, or hold intermediate results.

• Examples: int age = 25; String name = "John"; double salary = 5000.50;

An object is an instance of a class that encapsulates data and behavior. A class is a blueprint for creating objects.

• An object is a real-world entity with its own state and behavior.

• A class is a template or blueprint that defines the properties and methods of an object.

• Objects are created from classes using the 'new' keyword.

• Classes can be used to create multiple objects with similar characteristics.

• Objects can interact with each other by invoking methods and accessing proper...read more

Fibonacci series is a sequence of numbers where each number is the sum of the two preceding ones.

• The series starts with 0 and 1.

• Each subsequent number is the sum of the two previous numbers.

• The formula to calculate the nth Fibonacci number is F(n) = F(n-1) + F(n-2).

• Example: 0, 1, 1, 2, 3, 5, 8, 13, 21, ...