Core Java

Four Principles of OOP and Aggregation

Is Java a Pure Object Oriented Programming Language

Diamond Problem of Inheritance in Java 8

How does Mark and Sweep Work?

What are different Memory generations in java?

How will you troubleshoot Memory Issues in a Java application running in production?

Threading Jargons in java

What is Java Memory Model?

What is Producer Consumer Problem?

What is Non Blocking Algorithm? What is CAS?

Explain Internals of Concurrent HashMap

What is use of CopyOnWriteArrayList?

What is Volatile Variable?

What is ThreadLocalRandom? when should one use it over Random?

What is Dead Lock in Java

What are Immutable Objects? What is benefit of it?

What is Executors?

What is Thread Pool? How will you implement a basic thread pool from scratch?

What is Fork Join?

How are Concurrent Collections different from Normal Collections?

What is a Blocking Queue?

What is difference between ArrayBlockingQueue, DelayQueue and LinkedBlockingQueue in Java?

What is Semaphore?

What is CountDownLatch?

What is ThreadLocal Object? Give a example of its use?

What is CompletionService or ExecutorCompletion Service? Give a practical use case.

What is special about classes present in concurrent.atomic package? What is CAS?

What is Stamped Lock introduced in Java 8?

There are 3 different threads in a single method, how will you make then run sequentially?

What is difference between ArrayList and Vector?

What is difference between Hashmap and ConcurrentHashMap?

What is red-black-tree?

What is MinHeap?

What is Merge Sort? Which Sorting is used by Java Collections.sort() internally?

Write a simple Java program which will print Fibonacci series

Write a Program that calculates Prime Numbers in Java.

Write a program to check if a given String is Palindrome

Write a Program to check if given number is Armstrong number

Implement a Basic Token Bucket Algorithm in Java

Design and Implement a File Storage for millions of files. Consider that not more than 1000 files should be placed inside a single directory.

Implement a Web Crawler algorithm using Java

Design a Vending Machine in Java

Concept of Consistent hashing in distributed systems (Apache Cassandra)

Using Hashing to distribute the load horizontally

Head First Design Patterns

Head First Object Oriented Design and Analysis

Concurrency In Practice by Biran Goetz

Effective Java 2nd Edition