Hoisting in JavaScript Definition: Hoisting is JavaScript’s default behavior of moving declarations (not initializations) to the top of their scope — either the global scope or the function scope. This allows variables and functions to be used before they are formally declared in the code. In simple terms, during the compilation phase, JavaScript scans your […]
A wrapper class in Java is an object representation of primitive data types. Wrapper classes allow primitive types (e.g., int, double) to be treated as objects. Examples of Wrapper Classes: Primitive Type Wrapper Class int Integer char Character double Double float Float boolean Boolean byte Byte short Short long Long Why Do We Need Wrapper […]
Field injection in Spring (or any Dependency Injection framework) is not recommended because it has several drawbacks compared to other types of injection like constructor injection or setter injection. Below are the key reasons why field injection is discouraged and best practices advocate avoiding it: 1. Harder to Test Issue: Field injection makes it difficult […]
@Transactional is an annotation in Spring Framework that provides declarative transaction management. It is used to define the transactional behavior of a method or class, ensuring that database operations within the annotated scope are executed as part of a single transaction. Key Features of @Transactional Atomicity: Ensures that all operations within a transaction are treated […]
Here are several examples of lambda expressions in Kotlin to illustrate different use cases and syntactic styles. 1. Basic Lambda Expression A lambda expression is defined using curly braces {} with parameters and the arrow -> to separate parameters from the body.
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val greet = { name: String -> "Hello, $name!" } println(greet("Alice")) // Output: Hello, Alice! |
2. Lambda as a Parameter in a Function Passing a lambda expression […]
https://www.youtube.com/watch?v=9grEmpRfK0Y @Controller Vs @RestController How a spring boot application bootstraps? REST API Best practices Microservices interview questions Monolithic Architecture Vs Microservices Architecture How to manage IPs and servers in a microservices architecture How Service Discovery and Registration works? (A problem Scenario) How Client-side load balancing is different from Server-side load balancing? Is server-side load balancing […]
https://www.youtube.com/watch?v=yX2w-Sof95s Q1. @component vs @service vs @repository Q2. What will happen if you will use @service over a DAO? Q3. Explain spring Bean Lifecycle Q4. How you will call the @PreDestroy marked methods in the standalone application. Q5. Explain the helper class that initializes and destroys the web application context. Q6. What are the RestClients […]
Spring Boot Basics What is spring and spring boot Spring Boot Annotations List Spring Boot Lifecycle What is AutoConfiguration in Spring Boot and How to Override Spring Boot Core Concepts Dependency Injection in Context of Spring Boot What is Component Class What is Repository Class What is Service Class Difference Between Component, Service, Repository, Controller […]
To implement JWT token-based authentication in Spring Boot with MongoDB as the user store, we need to follow these steps: Add Dependencies for MongoDB, Spring Security, JWT, and Spring Web. Create MongoDB User Model and Repository. Create a Service to manage user registration and authentication. Create JWT Utility for token generation and validation. Create JWT […]
To implement JWT (JSON Web Token) authentication in a Spring Boot application, follow these steps: 1. Add Required Dependencies Add the following dependencies to your pom.xml if you’re using Maven. These are essential for Spring Security and JWT handling:
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<dependencies> <!-- Spring Web for building REST APIs --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- Spring Security for authentication --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-security</artifactId> </dependency> <!-- JWT library --> <dependency> <groupId>io.jsonwebtoken</groupId> <artifactId>jjwt</artifactId> <version>0.9.1</version> </dependency> </dependencies> |
2. Create a User Model You need to create a simple user model to hold […]