Mphasis Senior Software Engineer Interview Questions and Answers

Design patterns are reusable solutions to common problems in software design.

• Design patterns help in creating flexible, maintainable, and scalable software.

• Some common design patterns include Singleton, Factory, Observer, Strategy, and Decorator.

• Singleton pattern ensures a class has only one instance and provides a global point of access to it.

• Factory pattern creates objects without specifying the exact class of object...read more

Delegates are type-safe function pointers in C# used for implementing callbacks. async/await is used for asynchronous programming in C#.

• Delegates in C# are similar to function pointers in C or C++. They allow methods to be passed as parameters to other methods.

• Async/await in C# is used for asynchronous programming, allowing methods to run asynchronously without blocking the main thread.

• Delegates can be used with async/...read more

An interceptor is a design pattern commonly used in software development to capture and manipulate requests and responses.

• Interceptors can be used for logging, authentication, authorization, caching, error handling, etc.

• In Angular, interceptors can be used to modify HTTP requests before they are sent and responses before they are received.

• In Spring framework, interceptors can be used to intercept client requests and se...read more

Authentication is the process of verifying the identity of a user or system.

• Authentication involves confirming the identity of a user through credentials such as passwords, biometrics, or security tokens.

• Common methods of authentication include single-factor authentication (e.g. password) and multi-factor authentication (e.g. password + SMS code).

• Authentication can be achieved through protocols like OAuth, OpenID, SAML...read more

Handle exceptions globally in Springboot REST API

• Use @ControllerAdvice annotation to define global exception handling for all controllers

• Create a class annotated with @ControllerAdvice and define methods to handle specific exceptions

• Use @ExceptionHandler annotation to specify which exceptions the method should handle

• Return appropriate HTTP status codes and error messages in the exception handling methods

Microservices design pattern involves breaking down a large application into smaller, independent services.

• Each microservice is responsible for a specific function or feature

• Communication between microservices is typically done through APIs

• Microservices can be deployed independently, allowing for easier scalability and maintenance

• Examples include Netflix (uses microservices for different functionalities like recommenda...read more

Use Java Stream API to apply a 10% salary hike for employees with over 5 years of experience.

• Use a List<Employee> to store employee data.

• Filter employees with experience > 5 years using stream().filter().

• Map the filtered employees to update their salary by multiplying with 1.1.

• Collect the results back into a List using collect(Collectors.toList()).

• Example: employees.stream().filter(e -> e.getExperience() &g...read more

Map method transforms each element in a stream, while flatMap method transforms each element into a stream and then flattens the result.

• Map method applies a function to each element in the stream and returns a new stream with the transformed elements.

• FlatMap method applies a function that returns a stream for each element in the original stream, then flattens these streams into a single stream.

• Example: Using map to con...read more

Handling customized exceptions in controller advice with example code

• Create a custom exception class that extends RuntimeException

• Create a controller advice class to handle exceptions globally

• Use @ExceptionHandler annotation in the controller advice class to handle specific exceptions

• Return a custom error response with appropriate status code and message

The @SpringBootApplication annotation includes @Configuration, @EnableAutoConfiguration, and @ComponentScan annotations.

• Includes @Configuration annotation to specify that the class can be used by the Spring IoC container as a source of bean definitions.

• Includes @EnableAutoConfiguration annotation to enable Spring Boot's auto-configuration feature.

• Includes @ComponentScan annotation to specify the base packages to scan f...read more

Java program to count the number of repeated characters in a string

• Create a HashMap to store characters and their counts

• Iterate through the string and update the counts in the HashMap

• Print the characters with counts greater than 1

Cucumber architecture is a testing framework that supports Behavior Driven Development (BDD) by allowing tests to be written in plain language.

• Cucumber uses Gherkin syntax to define test cases in a human-readable format

• It separates the test logic from the test data using feature files and step definitions

• Cucumber integrates with various programming languages like Java, Ruby, and JavaScript

• It allows collaboration betwee...read more

Feature file for login page

• Create a feature file named 'login.feature'

• Define a scenario for successful login

• Define a scenario for unsuccessful login

• Include steps like entering username, password, clicking login button

• Use Given-When-Then format for scenarios

To avoid concurrent modification exception, use synchronized blocks or data structures like ConcurrentHashMap.

• Use synchronized blocks to ensure only one thread can modify the data at a time

• Use data structures like ConcurrentHashMap which are designed to handle concurrent modifications

• Consider using immutable objects to prevent modification conflicts

Using stream API for coding questions

• Use stream() method to convert a collection into a Stream

• Use filter() method to filter elements based on a condition

• Use map() method to transform elements into another form

• Use collect() method to collect the elements into a new collection