Versioning RESTful APIs with Spring Boot in 5 minutes

A Step-by-Step Guide to Implement API Versioning

API versioning is a crucial aspect of software development, especially when it comes to maintaining and extending an existing codebase. By implementing versioning, you can introduce new features without breaking the existing functionality. In this guide, we will walk you through how to implement API versioning in a Spring Boot application using URL versioning. We will create two versions of a simple Task API, allowing you to extend the features while minimizing the impact on existing logic.

Prerequisites

Before you begin, make sure you have the following prerequisites:

• Basic knowledge of Java and Spring Boot.
• A Spring Boot project set up.

Step by step to understand versioning in Spring boot

Step 1: Define the Task Class

The first step is to define the Task class, which will represent the data model for our API. Here's a basic example:

public class Task {
    private Long id;
    private String name;
    
    // Constructors, getters, setters, etc.
}

Step 2: Create the TaskService Interface

Create the TaskService interface, which will define the operations for managing tasks. This interface will serve as the contract for both API versions. For now, let's keep it minimal:

public interface TaskService {
    List<Task> getAllTasks();
    Task getTaskById(Long id);
    Task createTask(Task task);
    Task updateTask(Long id, Task task);
    void deleteTask(Long id);
}

Step 3: Create the TaskServiceV1Impl to extend TaskService:

@Service
@Qualifier("v1")
public class TaskServiceV1Impl implements TaskService {
    protected List<Task> tasks = new ArrayList<>();
    protected Long nextId = 1L;

    @Override
    public List<Task> getAllTasks() {
        return tasks;
    }
    @Override
    public Task getTaskById(Long id) {
        // Implementation for getting a task by ID
    }
    @Override
    public Task createTask(Task task) {
        // Implementation for creating a task
    }…