Foundation to Spring Boot Beginners

Nimasha Madhushani
4 min readJan 28, 2024
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Spring Boot is a lightweight, powerful framework, and built on top of the Spring Framework.

Spring Boot module provides a Rapid Application Development feature to the Spring framework.

📝Key points we should focus on learning about the Spring Boot,

1. Spring Initializer (

  • Web-based tool
  • Bootstrap Spring Boot projects
  • Allows to select relevant dependencies, packaging options, and project settings
  • Generate a customized project structure

2. Dependencies

  • Use as external modules/plugins to enhance the functionality of the project

3. Dependency Injection

  • A core concept in Spring Boot
  • Facilitate loose coupling by allowing management and inject dependencies to application components
  • Enhance the flexibility and maintainability

4. Maven/ Gradle

  • Spring Boot projects can be built using either Maven or Gradle
  • Easy to manage dependencies efficiently
  • Automatically fetch required libraries
  • Maintain the consistency of the project builds

5. Embedded HTTP Servers

  • Spring Boot has embedded HTTP servers like Tomcat
  • Eliminate the use of external server configurations
  • Simplify the deployment

6. JPA

  • Java Persistence API
  • Stands for ORM(Object Relational Mapping) in Java applications
  • Spring Boot provides easy integration with JPA for data access
  • Streamline database operations
  • Interact with database

7. Annotations

  • Use to simplify the configurations
  • Reducing boilerplate codes
  • Enhance the readability

8. Jar

  • Spring Boot applications are usually packaged as JAR(Java Archive) files
  • Standalone executable JAR simplifies deployment and execution

9. Lombok Library

  • Lombok is a Java library that helps reduce boilerplate code by automatically generating common code blocks such as getters, setters, and, constructors.
  • So, Lombok provides annotations. (We will discuss the annotations belonging to this Lombok library in the latter part of this article).
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The flow of Spring Boot Application

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A client that is responsible for interacting with the user and recent data


  1. Controller
  • Serving as an entry point for processing user inputs.
  • The controller can handle requests and responses.
  • Controller-received things are attached to a DTO and sent to the service layer.

2. API(Application Programming Interface)

  • RESTful APIs that allow communication between the frontend and backend.

3. DTO(Data Transferring Objects)

  • Objects used to transfer data between different layers of an application, typically between the frontend, controller, and service layers.

4. Service

  • Contain business logic and perform operations requested by controllers.

5. Entity

  • Represent objects stored in DB.
  • Most of the time entity will map the table in the DB

6 . Repository

  • Provide an abstraction for data access
  • Interact with databases to handle CRUD operations

7. Database

  • Stores and manages data persistently
  • Spring Boot supports various databases(MongoDB, MySQL, MSSQL, PostgreSQL)
  • Can use technologies like JPA to interact with databases easily



  • When the application runs, Hibernate, the JPA provider, creates a table in the database based on this entity.


  • Use to designate a field as the primary key of an entity
  • Signifies the unique identifier for database records


  • Used to declare custom queries in Spring Data JPA
  • Allows developers to define complex database operations(custom inserts or updates)


(response body + controller)

  • Responses are converted to XML/JSON automatically


  • Maps HTTP requests to handler methods in a controller

@GetMapping — Handle HTTP GET requests, and use for retrieving resources or data

@PostMapping — Handle HTTP POST requests, and used for creating or adding new resources

@PutMapping — Handle HTTP PUT requests, and used for updating existing resources or creating if not present

@DeleteMapping — Handle HTTP DELETE requests, and used for for deleting or removing resources


  • Cross-origin resource sharing when the frontend and backend are in two origins (It is blocked for a security reason)


  • Used for automatic dependency injection (If two things depend mostly on each other then as a dependency we can inject that into another class)


  • Identify the service layer when performing business logic or service-layer operations


  • Indicates that a method, or all methods in a class, should be executed within a database transaction.
  • Ensures consistency for database operations, preventing data inconsistencies.


  • These 2 annotations are provided by the Lombok Library.
  • @AllArgsConstructor generate a constructor with arguments for all fields in the class.
  • @NoArgsConstructor generates a constructor with no arguments.


  • Provided by the Lombok Library.
  • Generates a builder pattern for class.

@Getter / @Setter

  • Provided by the Lombok Library.
  • Generates getter and setter methods for the fields in the class.


  • Provided by the Lombok Library.
  • Generates a toString() method for the class, including all fields.


  • Provided by the Lombok Library.
  • This is a combination of @Getter, @Setter, @ToString, @EqualsAndHashCode, and @RequiredArgsConstructorannotations.
  • Generates common boilerplate code like getters, setters, toString, equals, hashCode, and constructors, streamlining Java class definitions.

In this article, I hope to make you aware of the background and the jargon you may know to learn Spring Boot. So, I will guide you to implement a simple Spring Boot application in the next blogs.

Stay tuned guys😎, until then bye byeeee…👋🏼👋🏼