One of the most common errors Spring Boot developers face is: Web server failed to start. Port 8080 was already in use This error usually appears when your Spring Boot application starts successfully, but the embedded web server (Tomcat/Jetty/Undertow) cannot bind to port 8080. In this guide, you’ll learn: This explanation works for Windows, macOS, […]

Your application starts successfully, the startup logs look clean, and there are no exceptions. But when you try to access an API endpoint, nothing happens—or you receive a 404, 403, or no response at all. This issue occurs not only during local development but also in production deployments and CI/CD environments. In this guide, you’ll