Lnv Digital Systems Java Developer Interview Questions and Answers

Q1. Explain architecture of your project
Add your answer
Q2. Some questions on Java, Spring Boot and sql
Add your answer

Q1. Project flow and some behavioural questions
Add your answer
Q2. Project contribution of yours
Ans. 
Developed a web application for tracking employee attendance and performance
• Implemented user authentication and authorization using Spring Security

• Utilized Hibernate for database interaction and data persistence

• Designed and developed RESTful APIs for frontend integration

• Used AngularJS for frontend development to create interactive user interfaces
Answered by AI
Add your answer

Q1. Basic formalities before offer release
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

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

Q1. Comparable vs Comparator
Ans. 
Comparable is an interface used for natural ordering, while Comparator is used for custom ordering in Java.
• Comparable interface is used to define the natural ordering of objects. It is implemented by the class whose objects are to be sorted.

• Comparator interface is used to define custom ordering of objects. It is implemented by a separate class that compares objects based on specific criteria.

• Example: Sorting a list of ...read more
Answered by AI
Add your answer
Q2. Difference between List and Set

Ans. 

List allows duplicate elements and maintains insertion order, while Set does not allow duplicates and does not maintain order.

• List can contain duplicate elements, Set cannot

• List maintains insertion order, Set does not guarantee order

• List is implemented by classes like ArrayList, LinkedList, Set is implemented by classes like HashSet, TreeSet

• Example: List list = new ArrayList<>(); Set set = new HashSet<>();

Add your answer