This is a series of articles about subjects I came across my preparations for interviews as a Java developer. I have created these firstly for my personal use but hopefully will help others too.
JPA (Java Persistence API) Basics JPA is a specification for ORM (Object-Relational Mapping) in Java. Common implementations: Hibernate, EclipseLink, OpenJPA. Core annotations: @Entity – Marks a class as a database entity. @Id – Specifies the pr...
JPA Repository: What It Is Used For and Main Features What is JPA Repository? JpaRepository is a part of Spring Data JPA, which provides a convenient way to interact with a relational database using JPA (Java Persistence API). It extends PagingAndSor...
Many coding problems in interviews are variations of common problem patterns. Recognizing these patterns and their solutions can help you solve many problems efficiently. Below is a breakdown of common problem categories similar to Two Sum and their ...
1. Key Goals of System Design Scalability: The system's ability to handle increased load by adding resources. Includes vertical scaling (more power to a single node) and horizontal scaling (adding more nodes). Reliability: Ensures the system contin...
Java Streams are part of the java.util.stream package introduced in Java 8. They provide a way to process sequences of data in a functional programming style. Streams can be used to perform operations like filtering, mapping, and reducing on collecti...
Java functional interfaces are a powerful feature for enabling functional programming in Java. Here's an overview: What are Functional Interfaces? A functional interface in Java is an interface that contains exactly one abstract method. They can have...
1. Basics of Threads A thread in Java is a lightweight process that enables concurrent execution of code. It allows multiple tasks to run in parallel within a single application. Key Concepts: Thread Lifecycle: New → Runnable → Running → Terminated ...
Spring AOP (Aspect-Oriented Programming) is a powerful feature of the Spring Framework that allows you to define cross-cutting concerns like logging, security, and transaction management in a clean and modular way. What is AOP? Aspect-Oriented Progra...
Design patterns in Java are categorized into three main types: 1. Creational Patterns These deal with object creation, ensuring flexibility and control. Singleton Pattern: Ensures only one instance of a class is created. Example: A class to manage ...