xkcoding/spring-boot-demo · info · JsonException

500

500

Error message

服务器出错啦

What it means

This is a demo/test endpoint (GET /json) that unconditionally throws a JsonException wrapping Status.UNKNOWN_ERROR (code 500, message '服务器出错啦'). It exists solely to demonstrate the global exception handler's JSON-response path. It will always fire when the endpoint is hit — it is not a runtime failure but a deliberate test throw.

Source

Thrown at demo-exception-handler/src/main/java/com/xkcoding/exception/handler/controller/TestController.java:26

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;

/**
 * <p>
 * 测试Controller
 * </p>
 *
 * @author yangkai.shen
 * @date Created in 2018-10-02 20:49
 */
@Controller
public class TestController {

    @GetMapping("/json")
    @ResponseBody
    public ApiResponse jsonException() {
        throw new JsonException(Status.UNKNOWN_ERROR);
    }

    @GetMapping("/page")
    public ModelAndView pageException() {
        throw new PageException(Status.UNKNOWN_ERROR);
    }
}

View on GitHub (pinned to 87a142f960)

Solutions

1. This is expected behavior for the demo — no fix needed unless the endpoint is unwanted.
2. If this appears in production logs, exclude or remove the TestController bean from production builds.
3. Verify a @ControllerAdvice with an @ExceptionHandler(JsonException.class) is registered to produce the expected JSON response.

// In a @ControllerAdvice handler
@ExceptionHandler(JsonException.class)
@ResponseBody
public ApiResponse handleJsonException(JsonException e) {
    log.warn("JsonException caught: code={}, msg={}", e.getCode(), e.getMessage());
    return ApiResponse.ofMessage(e.getCode(), e.getMessage());
}

When it happens

Trigger: Sending a GET request to /json. The method body contains no conditional logic — it always throws. The JsonException is caught by a @ControllerAdvice handler (if configured) and returned as a JSON ApiResponse with code 500.

Common situations: Hitting the demo endpoint during local testing; integration tests that exercise the exception-handler flow; accidental exposure of the test controller in a non-demo deployment.

AI-assisted analysis of xkcoding/spring-boot-demo@87a142f960 (2026-08-14). Data as JSON: /api/errors/eb50d5a636804e79. Report an issue: GitHub.