Spring Full-Stack Practical Cases

Sep 8, 2026 · Backend Development

Spring Boot 3: Auto-Convert URL JSON to Objects with @ConvertJson Annotation

This tutorial demonstrates how to create a custom @ConvertJson annotation in Spring Boot 3.5.0 that automatically fetches JSON from a URL parameter and converts it into a typed Java object, using HandlerMethodArgumentResolver and BeanPostProcessor for both method-parameter and field-level injection with SpEL support.