Dataspire Technologies Java Developer Interview Questions and Answers

A standard online test conducted through one of the testing platforms.

Q1. Java 8 features
Add your answer
Q2. Rest API
Add your answer
Q3. Java 8 coding problem
Add your answer
Q4. Collections
Add your answer

Q1. It was based on my previous project
Add your answer

Q1. Explain Spring Boot
Add your answer
Q2. What is Redux in React
Add your answer
Q3. What is Context API in React
Add your answer

Q1. What are primitive and non primitive data types
Ans. 
Primitive data types are basic data types provided by the programming language, while non-primitive data types are created by the programmer.
• Primitive data types include int, float, double, char, boolean, etc.

• Non-primitive data types include arrays, classes, interfaces, etc.

• Primitive data types store actual values, while non-primitive data types store references to objects.
Answered by AI
Add your answer
Q2. What are access modifiers and non access modifiers
Ans. 
Access modifiers control the visibility of classes, methods, and variables. Non-access modifiers provide additional functionality.
• Access modifiers: public, private, protected, default

• Non-access modifiers: static, final, abstract, synchronized

• Example: public class MyClass { private int myVar; }
Answered by AI
Add your answer
Q3. What are all Java 8 features and explain the one which we have used in our project
Ans. 
Java 8 features include lambda expressions, functional interfaces, streams, and more.
• Lambda expressions allow concise syntax for defining anonymous functions.

• Functional interfaces can have only one abstract method and are used for lambda expressions.

• Streams provide a way to process collections of objects in a functional style.

• Optional class helps to avoid NullPointerException by wrapping a value that may be null.
Answered by AI
Add your answer
Q4. CICD tools which we have used explain in high level
Ans. 
CICD tools automate the process of building, testing, and deploying code changes.
• Popular CICD tools include Jenkins, GitLab CI/CD, CircleCI, and Travis CI

• These tools help in automating the software development lifecycle

• They enable continuous integration, continuous delivery, and continuous deployment

• CICD tools help in improving code quality, reducing manual errors, and increasing development speed
Answered by AI
Add your answer
Q5. What is containerization
Ans. 
Containerization is a lightweight, portable, and self-sufficient way to package and run applications.
• Containerization involves encapsulating an application and its dependencies into a container image.

• Containers are isolated from each other and share the host OS kernel.

• Popular containerization platforms include Docker and Kubernetes.

• Containerization allows for easy deployment and scaling of applications.
Answered by AI
Add your answer
Q6. What is indexing in sql
Ans. 
Indexing in SQL is a technique used to improve the performance of queries by creating a data structure that allows for faster retrieval of data.
• Indexes are created on columns in a database table to speed up the retrieval of rows that match a certain condition in a query.

• They work similar to the index in a book, allowing the database to quickly locate the rows that satisfy the query.

• Indexes can be created using a single...read more
Answered by AI
Add your answer
Q7. Programming question on stream like finding the longest string in a given list of string
Add your answer

Q1. Tell me about your project
Ans. 
Developed a web-based inventory management system for a retail company.
• Used Java, Spring Boot, and MySQL for backend development.

• Implemented user authentication and authorization using Spring Security.

• Designed a responsive front-end using HTML, CSS, and JavaScript.

• Integrated barcode scanning functionality for efficient inventory tracking.
Answered by AI
Add your answer
Q2. Class vs object
Ans. 
A class is a blueprint or template for creating objects, while an object is an instance of a class.
• A class defines the properties and behaviors of objects, while an object is a specific instance of a class.

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

• Objects have state (attributes) and behavior (methods) defined by the class.

• Example: Class 'Car' defines properties like 'color' and 'model'...read more
Answered by AI
Add your answer

Q1. Salary expectation
Add your answer
Q2. Date to join?
Add your answer

Q1. Diff between abstract class and interface
Ans. 
Abstract class can have both abstract and non-abstract methods, while interface can only have abstract methods.
• Abstract class can have constructor, fields, and methods, while interface cannot have any of these.

• A class can extend only one abstract class, but can implement multiple interfaces.

• Abstract classes are used to define a common behavior among subclasses, while interfaces are used to define a contract for classes...read more
Answered by AI
Add your answer
Q2. Explain about handler methods
Ans. 
Handler methods in Java are methods that are responsible for handling incoming requests and generating responses.
• Handler methods are typically defined in classes annotated with @Controller or @RestController.

• These methods are mapped to specific URLs using @RequestMapping or other mapping annotations.

• Handler methods can have parameters such as HttpServletRequest, HttpServletResponse, or model attributes.

• The return value...read more
Answered by AI
Add your answer

Q1. Prime number program
Ans. 
A program to check if a given number is prime or not.
• Create a function to check if a number is prime by iterating from 2 to the square root of the number.

• If the number is divisible by any number other than 1 and itself, it is not prime.

• Handle edge cases like 0, 1, and negative numbers separately.
Answered by AI
Add your answer
Q2. 3rd highest salary employee
Ans. 
To find the 3rd highest salary employee, we can use a SQL query with the 'LIMIT' and 'OFFSET' keywords.
• Use a SQL query to select distinct salaries in descending order

• Use 'LIMIT 1 OFFSET 2' to get the 3rd highest salary

• Join this result with the employee table to get the employee details
Answered by AI
Add your answer

Q1. They asked some core Java Concepts,String,Java 8,SpringBoot Architecture,Stream API code
Add your answer

Aptitude questions and some questions from PostgreSQL.

Q1. Java fundamental questions?
Add your answer
Q2. Collection Framework.
Add your answer
Q3. 2-3 easy to medium Coding Questions.
Add your answer
Q4. Questions from Object oriented programming in Java?
Add your answer
Q5. Implementation of HashMap , LinkedList, HashSet, Heap?
Ans. 
HashMap, LinkedList, HashSet, and Heap are data structures commonly used in Java for storing and organizing data.
• HashMap: key-value pairs, uses hashing to store and retrieve elements efficiently (e.g. HashMap)

• LinkedList: linear data structure, elements are stored in nodes with pointers to the next node (e.g. LinkedList)

• HashSet: collection of unique elements, uses hashing to ensure uniqueness (e.g. Hash...read more
Answered by AI
Add your answer