How to Receive Request Parameters in Spring Boot - Choosing Between @RequestParam, @PathVariable, @RequestBody, and @ModelAttribute
A guide to the four annotations for receiving client input in Spring Boot Controllers—@RequestParam, @PathVariable, @RequestBody, and @ModelAttribute—with criteria for choosing between them based on the input source: query strings, path variables, JSON bodies, and forms. Covers required/defaultValue, multiple values with List, and the 400 behavior on type conversion failures with implementation examples.