10+ DTCC Interview Questions and Answers

Overloading is when multiple methods have the same name but different parameters, while overriding is when a subclass provides a specific implementation for a method in its superclass.

• Overloading involves multiple methods with the same name but different parameters.

• Overriding involves a subclass providing a specific implementation for a method in its superclass.

• Overloading is determined at compile time based on the method signature, while overriding is determined at runtime b...read more

Sleep method pauses the current thread for a specified amount of time, while join method waits for a thread to finish execution.

• Sleep method is a static method of Thread class, while join method is an instance method.

• Sleep method does not release the lock on the object, while join method does.

• Sleep method takes a specified time in milliseconds as an argument, while join method waits until the thread it is called on finishes execution.

• Example: Thread.sleep(1000) will pause the...read more

ArrayList is not synchronized while Vector is synchronized.

• ArrayList is not thread-safe, while Vector is thread-safe.

• Vector is slower than ArrayList because of synchronization.

• ArrayList is a part of the Java Collection Framework, while Vector is a legacy class.

• Example: ArrayList list = new ArrayList<>(); Vector vector = new Vector<>();

Annotations used in Spring framework for defining RESTful web services (@RestController) and MVC controllers (@Controller).

• Annotations in Spring framework for defining RESTful web services (@RestController) and MVC controllers (@Controller)

• @RestController is used for RESTful web services, @Controller is used for MVC controllers

• @RestController combines @Controller and @ResponseBody annotations

• Example: @RestController public class MyRestController {}

• Example: @Controller public ...read more

Use the equals() method or compareTo() method to compare two strings in Java.

• Use the equals() method to compare two strings for content equality.

• Use the compareTo() method to compare two strings lexicographically.

• Consider using the equalsIgnoreCase() method for case-insensitive comparison.

I know various docker commands for managing containers and images.

• docker run - to create and start a new container

• docker ps - to list all running containers

• docker stop - to stop a running container

• docker images - to list all available images

• docker pull - to download an image from a registry

• docker build - to build an image from a Dockerfile

A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image.

• Start with a base image using the FROM keyword

• Use the RUN keyword to execute commands in the image

• Use the COPY keyword to add files from your Docker client's current directory

• Use the CMD keyword to specify the command to run when the container starts

Git commands are used to interact with the version control system Git.

• git clone: Used to clone a repository from a remote server to your local machine.

• git add: Adds changes in the working directory to the staging area.

• git commit: Records changes to the repository.

• git push: Pushes changes to a remote repository.

• git pull: Fetches changes from a remote repository and merges them into the local branch.

Composition in Java is a design technique where a class contains an object of another class to reuse its functionality.

• Composition is a 'has-a' relationship, where one class contains an instance of another class.

• It allows for code reuse and flexibility in design.

• Example: A Car class may contain an Engine object, utilizing its functionality without inheriting from it.

No, static methods cannot be overridden in Java.

• Static methods belong to the class itself, not to any specific instance of the class.

• Subclasses can have static methods with the same signature as the parent class, but it is not considered overriding.

• Example: Parent class has a static method 'display()', and subclass also has a static method 'display()', this is not overriding.

Actuator in Spring Boot is a set of tools and features that help monitor and manage your application.

• Actuator provides endpoints to monitor application health, metrics, info, etc.

• It allows you to interact with your application through HTTP endpoints.

• Examples of endpoints include /actuator/health, /actuator/metrics, /actuator/info.

• Actuator can be customized and secured based on your requirements.

Data encapsulation is the concept of bundling data with the methods that operate on that data, restricting access to the data.

• Data encapsulation is a fundamental principle of object-oriented programming.

• It allows for the data to be hidden and only accessible through the defined methods.

• Encapsulation helps in achieving data abstraction and information hiding.

• Example: In a class representing a car, the variables like speed and fuel level can be encapsulated with methods like ac...read more

Spring MVC flow is the sequence of steps followed in processing a web request in a Spring MVC application.

• Client sends a request to the DispatcherServlet.

• DispatcherServlet sends the request to the appropriate Controller.

• Controller processes the request, interacts with the Model and returns a ModelAndView object.

• DispatcherServlet selects the appropriate ViewResolver to render the view.

• ViewResolver resolves the view and sends the response back to the client.

Thread life cycle refers to the various stages a thread goes through from creation to termination.

• Thread creation

• Thread start

• Thread running

• Thread waiting or blocked

• Thread termination

I handle exceptions by using try-catch blocks to catch and handle errors gracefully.

• Use try-catch blocks to catch exceptions and handle them gracefully

• Log the exception details for debugging purposes

• Throw custom exceptions when necessary

• Use finally block to clean up resources

Strings are immutable in Java to ensure thread safety, security, and optimization.

• Immutable strings are thread-safe as they cannot be modified concurrently by multiple threads.

• Immutable strings prevent security vulnerabilities like injection attacks.

• Immutable strings allow for optimization by caching and reusing string literals.

Point cut is a term used in Aspect-Oriented Programming (AOP) to define where certain aspects should be applied in the code.

• Point cut specifies the join points in the code where advice should be applied.

• It helps in separating the cross-cutting concerns from the main business logic.

• Examples of point cuts include method executions, field accesses, and exception handling.