DCB Bank Java Developer Interview Questions and Answers

final keyword can be used to make a variable's value constant and unchangeable

• Use 'final' keyword before the variable declaration

• Once a variable is declared as final, its value cannot be changed

• Example: final int num = 10; // value of num cannot be modified

Yes, deadlock is a situation in concurrent programming where two or more threads are waiting for each other to release resources, causing them to be stuck indefinitely.

• Deadlock occurs when two or more threads are blocked forever, waiting for each other to release resources.

• It can happen when multiple threads have locks on different resources and each thread is trying to acquire a lock held by another thread.

• Example: Th...read more

Use a HashSet to store unique elements from the arraylist

• Create a HashSet and add all elements from the arraylist to it

• Since HashSet does not allow duplicates, only unique elements will be stored

• Convert the HashSet back to an arraylist if needed

Conflicts can arise in git and github when multiple developers make changes to the same file or branch simultaneously.

• Conflicts can occur when two developers make changes to the same line of code in a file.

• Conflicts can also arise when merging branches that have diverged and contain different changes.

• Communication among team members is crucial to avoid conflicts and resolve them efficiently.

• Using pull requests and code...read more

Spring came into picture to simplify Java development by providing features like dependency injection, aspect-oriented programming, and transaction management.

• Spring provides dependency injection which helps in managing object dependencies and promotes loose coupling.

• It supports aspect-oriented programming for separating cross-cutting concerns like logging, security, and transaction management.

• Spring offers robust tran...read more

Polymorphism is the ability of a single function or method to operate on different types of data.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• There are two types of polymorphism: compile-time (method overloading) and runtime (method overriding).

• Example: A superclass Animal with methods eat() and sleep(). Subclasses Dog and Cat override these methods with their own imp

Collection framework in Java is a set of classes and interfaces that provide a way to store and manipulate groups of objects.

• It provides a way to store, retrieve, and manipulate groups of objects.

• It includes interfaces like List, Set, and Map, and classes like ArrayList, HashSet, and HashMap.

• Collections framework simplifies the process of working with collections of objects in Java.

Map is a collection of key-value pairs where keys are unique, while Set is a collection of unique elements with no duplicates.

• Map allows duplicate values but keys must be unique

• Set does not allow duplicate elements

• Map is accessed using keys, while Set is accessed using elements

• Example: Map - {1: 'apple', 2: 'banana'}, Set - {'apple', 'banana'}

ArrayList is a better choice when space is not an issue due to its constant time access, while LinkedList has better performance for insertions and deletions.

• ArrayList is better for random access as it provides constant time access to elements based on index.

• LinkedList is better for insertions and deletions as it does not require shifting elements in memory.

• Example: If you need to frequently add or remove elements in a...read more

JavaFX is a software platform for creating and delivering desktop applications, while JSP is a technology used for creating dynamic web pages.

• JavaFX is used for creating rich internet applications with a modern look and feel.

• JSP is used for developing dynamic web pages with Java code embedded in HTML.

• JavaFX and JSP can be used together to create interactive web applications.