With the recent surge in security vulnerabilities across the Spring ecosystem in the first half of 2026, relying on scattered security validation inside individual REST controllers is no longer an option—especially for banking and financial applications. Security must be tight, centralized, and fully auditable.
In this article, we will look at how to build an enterprise-grade API architecture that secures endpoints globally using a HandlerInterceptor and automatically logs every user transaction into a PostgreSQL database for a bulletproof audit trail.
1. Centralizing Request Validation with a HandlerInterceptor
Instead of repeating token extraction logic in every controller method, we can intercept incoming HTTP requests globally. This approach keeps our controllers thin and focused purely on routing.
First, let's create a centralized security interceptor that validates the token and extracts the necessary audit data:
