Capgemini Interview Questions and Answers

Java 8 introduced static and default methods in interfaces, allowing for method implementation and code reusability.

• Java 8 introduced static methods in interfaces, allowing for method implementation directly in the interface itself.

• Default methods were also introduced in Java 8, enabling interfaces to have method implementations without affecting implementing classes.

• Static methods in interfaces can be called using the...read more

HashMap is a data structure that stores key-value pairs and uses hashing to efficiently retrieve values.

• HashMap uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to determine the index in the array where it will be stored.

• If multiple keys hash to the same index, a linked list is used to handle collisions.

• To synchronize a HashMap, you can use the synchronizedMap() m...read more

No, the program will not compile if the parent class throws a runtime exception while the child class throws an arithmetic exception.

• In Java, if a parent class method throws a checked exception, the child class method can only throw the same exception or its subclasses.

• ArithmeticException is an unchecked exception, so if the parent class throws a checked exception and the child class throws an unchecked exception, the ...read more

Configure JDBC in Spring Boot to specify which database to use

• Define multiple DataSource beans in the configuration class

• Use @Primary annotation to specify the primary DataSource

• Use @Qualifier annotation to specify the secondary DataSource

• Inject the DataSource beans where needed in the application

To use a Jetty server in a Spring Boot application, you can configure it as a dependency and customize its settings.

• Add Jetty server dependency in your pom.xml file

• Exclude Tomcat server dependency if it's included by default in Spring Boot

• Configure Jetty server settings in application.properties or application.yml file

• Example: Add Jetty dependency - <dependency> <groupId>org.springframework.boot</groupId...read more

RequestParam is used to extract query parameters from the URL, while PathVariable is used to extract values from the URI path.

• RequestParam is used for query parameters in the URL, while PathVariable is used for values in the URI path.

• RequestParam is optional, while PathVariable is required.

• RequestParam is used with the @RequestParam annotation, while PathVariable is used with the @PathVariable annotation.

• Example: @Requ...read more

I would implement timeout mechanisms and retries to handle the scenario of one microservice awaiting a response from another microservice taking an extended time.

• Implement timeout mechanisms in the calling microservice to limit the waiting time for a response.

• Set up retry logic to automatically resend the request to the slow microservice if no response is received within the specified timeout period.

• Use circuit breaker...read more

SOLID principles in Java focus on object-oriented design principles. Java 8 features like lambdas and streams adhere to these principles.

• S - Single Responsibility Principle: Java 8 lambdas allow for defining single-purpose functions.

• O - Open/Closed Principle: Java 8 streams enable extending behavior without modifying existing code.

• L - Liskov Substitution Principle: Java 8 interfaces support polymorphism and substitutio...read more

A Singleton class in Java ensures that only one instance of the class is created and provides a global point of access to it.

• Use a private static instance variable to hold the single instance of the class.

• Make the constructor private to prevent instantiation from outside the class.

• Provide a public static method to access the single instance, creating it if necessary.

A controller is a component in the Model-View-Controller (MVC) design pattern that handles user input and updates the model and view accordingly.

• Controls the flow of the application

• Interacts with the model to update data

• Receives input from the user and processes it

• Updates the view based on changes in the model

• Examples: Spring MVC Controller, JavaFX Controller

Code to print unique elements from an array of strings

• Create a HashSet to store unique elements

• Iterate through the array and add elements to the HashSet

• Print out the elements in the HashSet to get unique elements

Code to find the second largest element in an array

• Iterate through the array and keep track of the largest and second largest elements

• Initialize variables to store the largest and second largest elements

• Compare each element with the largest and second largest elements and update accordingly

Hash collision occurs when two different inputs produce the same hash value. hashCode() and equals() methods are from Object class.

• Hash collision can occur when two different objects have the same hash code value.

• hashCode() method is used to get the hash code value of an object.

• equals() method is used to compare two objects for equality.

Circuit breaker is a design pattern used to prevent cascading failures in distributed systems.

• Circuit breaker monitors for failures and trips when a threshold is reached

• It then redirects calls to a fallback mechanism to prevent further failures

• Once the system stabilizes, the circuit breaker can be reset to allow normal operation

ControllerAdvice in Spring Boot is used for global exception handling in RESTful APIs.

• Create a class annotated with @ControllerAdvice

• Use @ExceptionHandler to define methods to handle specific exceptions

• Use @RestControllerAdvice for returning JSON responses

I have over 10 years of experience in designing and implementing complex software systems.

• Designed and implemented scalable software solutions for various clients

• Led a team of developers in delivering projects on time and within budget

• Worked closely with stakeholders to gather requirements and ensure customer satisfaction

I have used tools such as ANSYS, Abaqus, and SolidWorks Simulation for performing finite element analysis (FEA).

• ANSYS

• Abaqus

• SolidWorks Simulation

Basic knowledge of strength of materials and finite element method (FEM) is essential for analyzing structural behavior and designing components.

• Understanding of stress, strain, and material properties is crucial in analyzing the behavior of materials under different loading conditions.

• Knowledge of FEM helps in simulating complex structures and predicting their response to various loads.

• Ability to interpret FEM results...read more

SFD and BMD for cantilever beams of two different materials under point load P at free end

• Calculate reactions at the fixed end of the beam

• Determine the shear force at different points along the beam by considering the applied load and reactions

• Draw the SFD by plotting the shear force values against the beam length

• Calculate the bending moment at different points along the beam using the shear force values

• Draw the BMD by...read more

Static analysis is a software testing technique used to analyze code without executing it.

• Identify potential bugs and security vulnerabilities in the code

• Ensure code quality and adherence to coding standards

• Help in detecting performance issues and memory leaks

• Examples: linting tools like ESLint, static code analyzers like SonarQube

Implementing an explicit wait in Selenium using WebDriverWait class

• Import WebDriverWait class from Selenium

• Specify the maximum time to wait and the polling interval

• Use ExpectedConditions to define the condition to wait for

• Apply the wait to a specific element or the entire page

Implementing a Robot class in Java

• Create a Robot class with attributes like name, batteryLevel, etc.

• Include methods for moving, turning, and charging the robot

• Use inheritance if needed for different types of robots

To locate the Xpath for the 'Today's Deal' menu item on Amazon, inspect the element using browser developer tools.

• Open the Amazon website and right-click on the 'Today's Deal' menu item.

• Select 'Inspect' to open the browser developer tools.

• Look for the HTML code corresponding to the 'Today's Deal' menu item.

• Right-click on the HTML code and choose 'Copy' > 'Copy XPath'.

• The copied XPath can be used to locate the 'Today...read more

str1 will be stored in the string pool while str2 will be stored in the heap memory.

• str1 will be stored in the string pool, which is a part of the heap memory.

• str2 will create a new String object in the heap memory, separate from the string pool.

str1==str2 compares the memory addresses of the two strings, while str1.equals(str2) compares the actual contents of the strings.

• str1==str2 checks if the two string variables point to the same memory location.

• str1.equals(str2) compares the actual characters in the strings for equality.

• Example: String str1 = "hello"; String str2 = "hello"; str1==str2 will return false, but str1.equals(str2) will return true.

401 - Unauthorized, 502 - Bad Gateway

• 401 status code indicates that the request requires user authentication

• 502 status code indicates that the server received an invalid response from an upstream server

Print first 4 and last 4 letters of a given string

• Use string slicing to extract the first 4 letters: str[:4]

• Use string slicing to extract the last 4 letters: str[-4:]

HashMap is unordered, uses hashing for key-value pairs. TreeMap is ordered, uses Red-Black tree for key-value pairs.

• HashMap uses hashing to store key-value pairs, allowing for O(1) retrieval time on average.

• TreeMap uses Red-Black tree to store key-value pairs, maintaining order based on keys.

• HashMap allows one null key and multiple null values, while TreeMap does not allow null keys.

• Example: HashMap<String, Integer&...read more

A functional interface in Java is an interface with a single abstract method, enabling lambda expressions and method references.

• A functional interface can have multiple default or static methods.

• Common examples include Runnable, Callable, and Comparator.

• It is annotated with @FunctionalInterface for clarity.

• Lambda expressions can be used to instantiate functional interfaces.

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

• Singleton pattern restricts instantiation of a class to one object.

• It is commonly used for logging, driver objects, caching, and thread pools.

• Example in Java: Use a private constructor and a static method to get the instance.

• Thread-safe implementation can be achieved using synchronized methods or double-checked locking.

Eureka Server is a service registry for microservices in a cloud environment.

• Eureka Server is part of Netflix OSS and allows microservices to register themselves and discover other services.

• It helps in load balancing and failover of services by keeping track of available instances.

• Eureka Server uses a REST API for communication between services and the server.

• Example: Microservices A, B, and C register themselves with ...read more

Exception handling in SpringBoot involves using @ExceptionHandler, @ControllerAdvice, and global exception handling.

• Use @ExceptionHandler annotation in controller classes to handle specific exceptions.

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

• Implement a custom exception handler class to handle exceptions globally.

• Use ResponseEntity to return custom error messages and stat...read more

Calculate average salary of employees in each department using Java 8 Stream.

• Use Java 8 Stream to group employees by department

• Calculate average salary for each department using Stream's 'collect' method

• Use 'Collectors.averagingDouble' to calculate average salary

Circuit Breaker is a design pattern used in software development to prevent cascading failures in distributed systems.

• Circuit Breaker monitors the health of a service and stops sending requests if the service is not responding properly.

• It helps in improving the resilience of the system by providing a fallback mechanism when a service is down.

• Circuit Breaker can be configured with thresholds for error rates or response ...read more

Docker is a platform for developing, shipping, and running applications in containers. Kubernetes is an open-source system for automating deployment, scaling, and management of containerized applications.

• Docker allows developers to package applications and dependencies into containers for easy deployment and scalability.

• Kubernetes helps in automating the deployment, scaling, and management of containerized applications...read more

Multi cast in Angular allows multiple subscribers to receive the same data from a single source.

• Used to broadcast data to multiple subscribers

• Helps in reducing duplicate API calls

• Can be implemented using Subjects in RxJS

Event emitter is used in Angular to facilitate communication between components by emitting events.

• Event emitter is a class in Angular that allows components to emit custom events.

• It is used to facilitate communication between parent and child components.

• Parent components can subscribe to these events and react accordingly.

• Example: Child component emitting an event to notify the parent component about a change.

Use RxJS to handle multiple API calls efficiently in Angular.

• Use RxJS operators like forkJoin, combineLatest, or mergeMap to handle multiple API calls concurrently or sequentially.

• Consider using catchError operator to handle errors and retry operator to retry failed API calls.

• Use switchMap operator to cancel previous API calls when making new ones to avoid memory leaks.

• Utilize subjects or BehaviorSubjects to share data...read more

Child route is used for nested routes within a parent route, while forRoot is used for configuring routes at the root level of the application.

• Child routes are defined within the parent route's configuration, allowing for nested routing structures.

• forRoot is used in the AppRoutingModule to configure routes at the root level of the application.

• Child routes are typically used for organizing and managing related component...read more