Pretty Exception – Spring Boot Starter

A lightweight Spring Boot starter that replaces the default white-label error page with a clean, readable, developer-friendly exception view. It highlights the exact source line where the exception occurred and displays detailed request, environment, and system info — all in one page.

✨ Features:

• Pretty HTML exception page using Thymeleaf
• Automatic source-code extraction with highlight.js
• Highlights the exact line that triggered the exception
• Displays full request details (headers, params, origin, user-agent, etc.)
• Shows Java version Spring Boot version, Spring Active profiles, OS information
• Enabled automatically only when:
  • The application is a Servlet web app
  • The JAR is not deployed as a WAR
  • The property pretty-exception.enabled=true

🖥️ How It Works

• The starter auto-registers a custom HandlerExceptionResolver that:
• Captures uncaught exceptions
• Extracts the file and line where the exception occurred
• Reads the source file safely
• Sends a rich model containing:
• Exception details
• Extracted source code
• Request info
• Headers, params
• System + environment details
• Renders a detailed HTML page via Thymeleaf

🧪 Development Notes

• Starter automatically hooks into Spring Boot auto-configuration
• Uses @ConditionalOnProperty to turn feature on/off
• Uses @ConditionalOnWebApplication to avoid triggering in non-web apps
• Works with Spring Boot 2.7+
• Servlet-only (not reactive)