Code Pumpkin

Wissen Infotech Interview Questions – Set 1

September 12, 2017
Posted by Rahul Jain

I have appeared for Java Developer requirement at Wissen Infotech, Bangalore Location. Requirement was for their client Morgan Stanley and it was my second technical round. It was a telephonic interview. Duration : 1 hour

Core Java

  1. What is the difference between CountDownLatch and CyclicBarrier.  (Answer)
  2. What is the time complexity of put() and get() operation in HashMap? (Answer)
  3. Why do we need thredpool in Java Application?  (Answer)
  4. What is the time complexity of put() and get() operations in ConcurrentHashMap?
  5. How ConcurrentHashMap works internally?
  6. If Concurrency level of ConcurrentHashMap is 4, can more than four thread read simultaneously from ConcurrentHashMap?
    Answer  : Yes. Any number of threads can read concurrently from ConcurrentHashMap.
  7. If one thread is writing in one segment of ConcurrentHashMap, Can other thread read from that segment?
    Answer : Yes. In that case, reading thread will read last updated value as value field is volatile in ConcurrentHashMap entry object.
  8. What is the difference between synchronized keyword and ReentrantLock? Advantages of ReentrantLock over synchronized keyword.


  1. What is the difference between clustered and non-clustered index?

Problem Solving

  1. Print 1 to 20 numbers using two different threads concurrently.

Thread 1 prints 1, 3, 5, 7,…,19
Thread 2 prints 2, 4, 6, 8,…,20

  1. Find the intersection of two singly linked list? 

For Example, 
    First LinkedList       :  1 -> 2 -> 3 -> 4 -> 5
    Second LinkedList :  10 -> 9 -> 8 -> 7 -> 4 -> 5 

LinnkedList InterSection - Wissen Infotech Interview Questions – Set 1

Answer should be 4 i.e. both the lists are same after 4.

  1. I am having website which displays best three prices of the same product from different eCommerce sites.

For Example, 
        Price of Samsung Galaxy S8 is
        64000/- INR on Flipkart
        60000/- INR on Amazon
        66000/- INR on eBay
        63000/- INR on bestBuy
        67000/- INR on Infibeam
Our site should display Amazon, bestBuy and Flipkart prices for Samsung Galaxy S8.
Each e-commerce website sends frequent request for any update in price.
For processing such request we are having below method signature. 
We need to implement this method such a way that we will ignore such request, if we have already received request in last one hour for the same product from the same e-Commerce site. We need to handle multiple requests concurrently.
Explain the logic or the flow of your method?
Which data structure you will use and why?

This article is contributed by Rahul Jain. If you would also like to contribute your article or share interview experiences, you can create contributor account with codePumpkin by clicking here.

That's all for this topic. If you guys have any suggestions or queries, feel free to drop a comment. We would be happy to add that in our post. You can also contribute your articles by creating contributor account here.

Happy Learning 🙂

If you like the content on CodePumpkin and if you wish to do something for the community and the planet Earth, you can donate to our campaign for planting more trees at CodePumpkin Cauvery Calling Campaign.

We may not get time to plant a tree, but we can definitely donate ₹42 per Tree.

About the Author

Tags: , , , , , ,

Comments and Queries

If you want someone to read your code, please put the code inside <pre><code> and </code></pre> tags. For example:
<pre><code class="java"> 
String foo = "bar";
For more information on supported HTML tags in disqus comment, click here.
Total Posts : 124
follow us in feedly

Like Us On Facebook