Markit Java Interview Questions

Explain the concept of String immutability. What is String pool. How will you create your own String like class.

Explain Serialization. Overriding writeObject method.

What is a class loader.

What are Java locks. class level lock vs lock on objects.

HashMap, ConcurrentHashMap, TreeSet internal implementation.

What are Cyclic barrier and countdown latch.

Implement producer-consumer problem in core java.

How to make a Lock object wait for lock.

How will you implement your own thread-safe Semaphore in Core Java?

You have an input stream of millions of numbers. Which is the suitable data structure for this kind of situation?

What is "Hashing" concept and how is it implemented in java.

Design your own Queue, PriorityQueue(using heap).

Program to find the highest prime number less than a given number.

Design a stack using linked list

Write a program to implement a binary search tree and print the elements in-order.

Discussion on singleton design pattern: lazy initialization, eager initialization, also using inner classes. Difference between different approaches. why is one better than another?

Which one is better constructor injection or setter injection.

What is cyclic dependency of beans, how will you resolve that?

What is Left Outer Join in RDBMS.

SQL question including joins, group by

1 puzzle: there is a 2d array. the numbers in the array increase as you go down and as you move from left to right. find any given number with minimum complexity.

A probability question (probability of getting minimum two 3’s if i roll 2 dice).