1. Core Java
- CopyOnWriteArrayList
- Reflection API
- Threading
- Difference between Process and Thread
- Different ways to start a thread
- Thread lifecycle/states
- Runnable vs Callable
- Sleep vs Wait
- Wait vs Join
- Thread-Safe
- ExecuterService
- Difference between class lock and object lock?
- Best of Java Multithreading Interview Questions
- Collections
- Collection vs Collections
- Hashmap vs ConcurrentHashmap
- Set which maintains the order
- Hashmap vs HashTable
- JVM
- Java memory management
- Class loader
- String
- String vs StringBuilder vs StringBuffer
- Why String is immutable object ? what happens if it would be a mutable object ?
- How to make object as immutable ?
- Serialization ?
- Comparator vs Comparable
- Loop
- Break vs Continue
- Deep copy vs Shallow copy
- Object
- Why do we need to override equals() and hashCode() method ? What is the importance of equals() and hashCode() methods ?
2. Microservices
- How do you maintain data consistency across multiple services if all services connects to same DB and updates same table simultaneously ?
- What are all the design patterns available in microservices ?
- What is SAGA design pattern ?
3. Design Patterns
4. Hibernate
- Difference between JPA and Hibernate ?
- What are all the relationships available in hibernate ?
- What are all the caches mechanism available in Hibernate ?
- How do you implement second level cache ?
- Difference between get and load method ?
- How do you initialize hibernate session ?
4. Design Principles
- Why do you need design principles ?
- What are all the design principles you use in your project ?
5. Spring Boot
6. Spring Framework
- What is @Transactional annotation ? What it does ?
- What are the types of Isolation levels ?
- What are the propagation types ?
- What is @RestController
7. Spring security
- Explain how security flow works in your project ?
- What consists of JWT token ?
- What is OAuth mechanism ?
- What is OpenId connect ?
- Difference between Authentication and Authorization ?
8. DevOps
- How do you implement CI/CD in your project ?
- What is CI/CD pipeline concept
9. DB
- Joins
- Unions
- Simple queries using rownum
- Procedure
- Views
- Stored Procedure
- Performance comparison of SQL queries/views/stored procedures
- Aggregate functions
10. Java coding questions
- I have of a list of employees. I want to retrieve only the employees from dept 1. Write a program in java 8.
11. UI
- Difference between Angular and React.
12. Functional Programming
- Difference between object oriented and functional programming
Updated: June 30, 2024 at 9:27 am