spring boot api key authentication example

To implement API key authentication in a Spring Boot application, you can follow these steps:

1. Define a configuration class: Create a class, let's call it ApiKeyConfig, and annotate it with @Configuration. Inside this class, define a @Bean method that returns an instance of ApiKeyFilter, which we'll create in the next step.

2. Create an API key filter: Implement a class called ApiKeyFilter that extends OncePerRequestFilter. Override the doFilterInternal method to intercept incoming requests. Inside this method, retrieve the API key from the request headers or query parameters.

3. Validate the API key: In the doFilterInternal method, validate the API key by comparing it with a list of valid keys. You can store the valid keys in a configuration file, a database, or any storage mechanism of your choice.

4. Handle authentication failures: If the API key is invalid or missing, you can return an appropriate HTTP response, such as a 401 Unauthorized error.

5. Register the filter: In your ApiKeyConfig class, use the @Bean annotation to register the ApiKeyFilter as a filter bean. This ensures that the filter is applied to incoming requests.

6. Secure API endpoints: To apply API key authentication to specific endpoints, you can use Spring's method-level security annotations, such as @PreAuthorize or @Secured. Annotate the controller methods or classes that you want to secure with these annotations and specify the required roles or authorities.

That's it! With these steps, you have implemented API key authentication in your Spring Boot application. Remember to customize the implementation based on your specific requirements and security needs.