Spring Boot Tutorial | Full Course [2023] [NEW]

Introduction

This tutorial provides a comprehensive guide to getting started with Spring Boot, a popular Java framework for building stand-alone, production-ready applications. Through this guide, you'll learn how to set up your environment, create a simple API, and implement key features like database connectivity and dependency injection.

Step 1: Set Up Development Environment

• Install Java Development Kit (JDK): Ensure you have JDK installed on your machine. You can download it from the Oracle website or use OpenJDK.
• Choose an Integrated Development Environment (IDE): Recommended IDEs include IntelliJ IDEA or Eclipse. Download and install your preferred IDE.

Step 2: Create a New Spring Boot Project

• Use Spring Initializr:
  • Go to Spring Initializr.
  • Select the following options:
    • Project: Maven Project
    • Language: Java
    • Spring Boot: Choose the latest stable version.
    • Project Metadata: Fill in the Group and Artifact fields.
    • Dependencies: Add relevant dependencies like Spring Web, Spring Data JPA, and your database of choice (e.g., H2, MySQL).
  • Click on "Generate" to download your project.

Step 3: Open the Project in Your IDE

• Import the Project:
  • Open your IDE and import the downloaded project as a Maven project.
  • Wait for the IDE to download necessary dependencies.

Step 4: Start the Spring Boot Server

• Run the Application:
  • Open the main application class (annotated with @SpringBootApplication).
  • Run the application by executing the main method.
  • Check the console for a message indicating that the application has started successfully.

Step 5: Create a Simple API

• Define a Student Class:
  • Create a new class named Student with fields like id, name, and email.
  • Annotate the class with @Entity to indicate it’s a JPA entity.

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Student {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private String email;

    // Getters and Setters
}

Step 6: Create the API Layer

• Define a REST Controller:
  • Create a class named StudentController annotated with @RestController.
  • Implement methods for CRUD operations (Create, Read, Update, Delete).

import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/students")
public class StudentController {

    // Inject the student service

    @GetMapping
    public List<Student> getAllStudents() {
        // Logic to return all students
    }

    @PostMapping
    public Student saveStudent(@RequestBody Student student) {
        // Logic to save student
    }

    // Additional methods for update and delete
}

Step 7: Implement the Business Layer

• Create a Service Class:
  • Implement the business logic for managing students in a separate service class.
  • Use dependency injection to include the repository for database operations.

import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class StudentService {

    // Inject the student repository

    public List<Student> findAll() {
        // Logic to find all students
    }

    public Student save(Student student) {
        // Logic to save student
    }

    // Additional business methods
}

Step 8: Connect to a Database

• Configure Database Properties:
  • Open application.properties and add the database connection details.

spring.datasource.url=jdbc:mysql://localhost:3306/mydb
spring.datasource.username=root
spring.datasource.password=password
spring.jpa.hibernate.ddl-auto=update

Step 9: Use JPA Repository

• Create a Repository Interface:
  • Extend JpaRepository in a new interface for the Student entity.

import org.springframework.data.jpa.repository.JpaRepository;

public interface StudentRepository extends JpaRepository<Student, Long> {
}

Step 10: Test Your API

• Use Postman or Curl:
  • Test your API endpoints by sending requests to your application.
  • Ensure you can create, retrieve, update, and delete students successfully.

Conclusion

You have now set up a Spring Boot application with a simple REST API for managing students. You learned how to create a Spring Boot project, implement a basic API, connect to a database, and test your application. As a next step, consider exploring more advanced topics such as security, testing, and deploying your application.