Building CRUD APIs with Spring Boot and JPA

 Creating CRUD (Create, Read, Update, Delete) APIs is a fundamental task in any backend development project. With Spring Boot and Spring Data JPA, building these APIs becomes fast, efficient, and maintainable. Let’s explore how you can build a CRUD REST API using Spring Boot and JPA in just a few simple steps.

Step 1: Project Setup

Start by creating a new Spring Boot project using Spring Initializr with the following dependencies:

Spring Web

Spring Data JPA

H2 Database (for demo/testing)

You’ll get a basic project structure with all the necessary configurations.

Step 2: Define the Entity

Create a simple entity class that maps to a database table.

@Entity

public class Employee {

    @Id

    @GeneratedValue(strategy = GenerationType.IDENTITY)

    private Long id;

    private String name;

    private String role;

    // Getters and Setters

}

Step 3: Create the Repository

Extend JpaRepository to handle database operations automatically.

public interface EmployeeRepository extends JpaRepository<Employee, Long> {

}

Spring Data JPA will generate all basic CRUD methods for you—no implementation required.

Step 4: Build the REST Controller

Now, expose the CRUD operations via RESTful endpoints.

@RestController

@RequestMapping("/employees")

public class EmployeeController {

    @Autowired

    private EmployeeRepository repository;

    @PostMapping

    public Employee create(@RequestBody Employee emp) {

        return repository.save(emp);

    }

    @GetMapping

    public List<Employee> getAll() {

        return repository.findAll();

    }

    @GetMapping("/{id}")

    public ResponseEntity<Employee> getById(@PathVariable Long id) {

        return repository.findById(id)

            .map(ResponseEntity::ok)

            .orElse(ResponseEntity.notFound().build());

    }

    @PutMapping("/{id}")

    public Employee update(@PathVariable Long id, @RequestBody Employee emp) {

        emp.setId(id);

        return repository.save(emp);

    }

    @DeleteMapping("/{id}")

    public void delete(@PathVariable Long id) {

        repository.deleteById(id);

    }

}

Step 5: Test the API

You can now test the endpoints using tools like Postman or cURL. The in-memory H2 database makes it easy to verify changes instantly.

Final Thoughts

Spring Boot and JPA offer a powerful combo for building REST APIs with minimal effort. With auto-configuration, annotation-driven development, and built-in CRUD functionality, you can develop robust backend services quickly. This setup is perfect for microservices, web apps, and enterprise-level systems alike.

Learn  Full Stack Java Training

Introduction to Spring Boot for Java Developers

Creating Your First REST API with Spring Boot

Dependency Injection and Inversion of Control

Spring Boot Auto-Configuration Explained

Visit Our Quality Thought Training Institute



Comments

Post a Comment

Popular posts from this blog

Understanding the useEffect Hook

 React is primarily used for building user interfaces, where components re-render based on changes in state or props. But real-world applications often need to interact with external systems—fetching data, subscribing to events, updating the DOM, or starting timers. These are known as side effects, and React’s useEffect hook is the tool designed to handle them in functional components. What is useEffect? The useEffect hook lets you perform side effects in your component. It's React’s way of combining several lifecycle methods from class components (like componentDidMount, componentDidUpdate, and componentWillUnmount) into a single, unified API. Syntax : useEffect(() => {   // side effect code   return () => {     // cleanup code (optional)   }; }, [dependencies]); The first argument is a function containing your side effect logic. The optional second argument is a dependency array that controls when the effect runs. jsx Basic Example import React, { u...
Read more

What Is Tosca? A Beginner’s Guide

 In today’s fast-paced digital world, software testing has become more critical than ever. Businesses rely on flawless applications to maintain a competitive edge, and automation is the key to ensuring quality at speed. One powerful tool that has gained significant popularity in the test automation world is Tosca. Whether you're a tester, developer, or just curious about automation, this guide will help you understand what Tosca is and why it's important. What Is Tosca? Tosca is a test automation tool developed by Tricentis, designed to automate end-to-end testing for a wide range of applications. It supports web, mobile, desktop, API, and enterprise applications like SAP and Salesforce. Tosca is widely known for its model-based testing approach, which simplifies the automation process and reduces maintenance efforts. Unlike traditional scripting tools, Tosca doesn’t require deep coding knowledge, making it suitable for both technical and non-technical testers. Key Features of ...
Read more

Exception Handling in Java

In Java, exception handling is a powerful mechanism that helps developers manage runtime errors, ensuring the smooth execution of programs. Rather than crashing the program, exceptions allow you to identify the error, handle it gracefully, and keep the application running. What Is an Exception? An exception is an unwanted or unexpected event that disrupts the normal flow of a program. These can be caused by user errors, logic errors, or system issues. Java categorizes exceptions mainly into two types: Checked Exceptions – Handled during compile-time (e.g., IOException, SQLException). Unchecked Exceptions – Occur during runtime (e.g., NullPointerException, ArithmeticException). Why Handle Exceptions? Without exception handling, an error can cause your program to terminate unexpectedly. Handling exceptions: Increases program reliability Helps in debugging and troubleshooting Improves user experience by displaying meaningful error messages Basic Exception Handling Syntax Java provides fiv...
Read more