Problem Details for Errors

@RestControllerAdvice and ProblemDetail

A @RestControllerAdvice class handles exceptions for all controllers in one place. Returning Spring's ProblemDetail produces RFC 9457 problem details JSON (type, title, status, detail, instance), a standard format clients can parse consistently. Map domain exceptions (not found, conflict, forbidden) to the right status codes, and never leak stack traces or internal messages to clients.

An exception handler returning ProblemDetail

This file is from a demo "shop" service generated by start.spring.io for Spring Boot 4.1.1 and Java 21 (Temurin 21.0.12), built with Maven 3.9.16; the project compiled and its tests passed. ProductNotFoundException becomes a 404 problem-details response with a clear title and detail.

package com.example.shop;

import org.springframework.http.HttpStatus;
import org.springframework.http.ProblemDetail;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

@RestControllerAdvice
public class ApiErrors {
    @ExceptionHandler(ProductNotFoundException.class)
    public ProblemDetail notFound(ProductNotFoundException e) {
        ProblemDetail pd = ProblemDetail.forStatusAndDetail(HttpStatus.NOT_FOUND, e.getMessage());
        pd.setTitle("Product not found");
        return pd;                                   // RFC 9457 problem details JSON
    }
}

Requesting a missing product, run

I packaged the demo with mvn package, started it with java -jar on port 8085 and called it with curl; the output is copied from that run. The handler returns status 404 with the problem-details fields.

curl -s -w " [%{http_code}]" localhost:8085/api/products/99

Output:

{"detail":"Product 99 not found","instance":"/api/products/99","status":404,"title":"Product not found"} [404]

त्वरित जाँच: What is RFC 9457?

• A standard JSON format for HTTP API problem details
• A Java version
• A database isolation level
• A logging library