Sapient Global Market Java Interview Questions and Coding Exercise

How do we synchronize a static method to prevent data corruption in concurrent update?

How will you introduce multi-tasking in your java application?

Design a program to search files inside a directory using multi-threading?

How will you implement a LRU timed cache in Java?

There is a folder containing multiple SQL files. Each file’s name contain a sequence number which determines the execution order of that particular SQL script file. Design an API that will take such folder and execute the SQL in correct order.

What is difference between wait() and sleep() method?

What is a deadlock situation? How will you handle deadlock in development and production environment?

What is mechanism for inter-thread communication?

Would adding multi-threading to sorting algorithm improve its performance?

In what practical scenario’s multi-threading actually improves the performance of Java application?

Do we need to synchronize getter and setter both to prevent concurrency related issues on a collection?

Explain the key classes in java.util.concurrent package?

What is purpose of ConcurrentHashMap?

What is purpose of a Future? How will you use it?

How will you create your own custom threadpool in java without executor framework?

What is a BlockingQueue?

Complete Solution to Delhi Metro Design using Spring MVC with testcases

Sapient Fee calculator: Coding problem in Java
Solution to Sapient Fee Calculator discussed here

Designing Smart Card System for Delhi Metro
Solution to Delhi Metro Smart Card. implement 'Metro Smart Card System' (MSCS) for Delhi city. For application assume there is a single metro line covering 10 stations linearly. The stations name are A1, A2, A3, A4, A5, A6, A7, A8, A9, A10 as shown below. The travel can be in any direction.

Travelers have smart cards that behave just like any regular debit card that has an initial balance when purchased. Travelers swipe-in when they enter a metro station and swipe-out when they exit. The card balance is automatically updated at swipe-out.

Objective of the exercise is to create an automated system that has following functionality:

2.1 Card should have a minimum balance of Rs 5.5 at swipe-in. At swipe-out, system should calculate the fare based on below strategies set at the start of the day. The fare must be deducted from the card.
2.2 Card should have the sufficient balance otherwise user should NOT be able to exit.
     Weekday – Rs. 7 * (Number of stations traveled)
     Weekend – Rs. 5.5 * (Number of station traveled if it's Saturday or Sunday)
     (* there can be more such fare strategies in future)

There is three file contains flight data. File data has in csv format. 1)Write a standalone program to search flight detail from all files depend on criteria 2)Criteria would be departure location,arrival location, flight date. 3)Program should follow\Oops principle. And right unit test case also. 4)Result should be in Ascending or descending order. 5)Data separated with pipe | .

File A has data like below:
FLIGHT_NUM|DEP_LOC|ARR_LOC|VALID_TILL|FLIGHT_TIME|FLIGHT_DURN|FARE
AF299|FRA|LHR|20-11-2010|0600|4.10|480
AF118|DUB|MUC|21-12-2010|1410|5.40|580
AF371|AMS|MAD|30-11-2010|1210|3.45|320

File B has data like below:
FLIGHT_NUM|DEP_LOC|ARR_LOC_VALID_TILL|FLIGHT_TIME|FLIGHT_DURN|FARE
BA123|DEL|AMS|12-10-2010|0050|8.00|950
BA412|BOS|CDG|31-12-2010|0210|7.50|800
BA413|BOS|AMS|30-11-2010|1530|7.00|750

File C has data like below:
FLIGHT_NUM|DEP_LOC|ARR_LOC_VALID_TILL|FLIGHT_TIME|FLIGHT_DURN|FARE
LH348|DEL|AMS|30-11-2010|2325|11.00|1050
LH201|LHR|MEL|21-11-2010|0230|15.30|1400
LH342|VIE|JFK|20-10-2010|1130|14.20|980

Code Completeness/ Correctness

Code Structure and quality: Modularity, usage of OO principles, size of classes/functions,

Choice of data structures

Unit Test cases

Coding productivity (more time you take to submit the exercise, lesser you will score)

class/function/variable names, package/class structure