Spring Boot Rest - How to configure 404 - resource not found

Question

I got a working spring boot rest service. When the path is wrong it doesn\'t return anything. No response At all. At the same time it doesn\'t throw error either. Ideally I expe

Answer 1

The solution is pretty easy:

First you need to implement the controller that will handle all error cases. This controller must have @ControllerAdvice -- required to define @ExceptionHandler that apply to all @RequestMappings.

@ControllerAdvice
public class ExceptionHandlerController {

    @ExceptionHandler(NoHandlerFoundException.class)
    @ResponseStatus(value= HttpStatus.NOT_FOUND)
    @ResponseBody
    public ErrorResponse requestHandlingNoHandlerFound() {
        return new ErrorResponse("custom_404", "message for 404 error code");
    }
}

Provide exception you want to override response in @ExceptionHandler. NoHandlerFoundException is an exception that will be generated when Spring will not be able to delegate request (404 case). You also can specify Throwable to override any exceptions.

Second you need to tell Spring to throw exception in case of 404 (could not resolve handler):

@SpringBootApplication
@EnableWebMvc
public class Application {

    public static void main(String[] args) {
        ApplicationContext ctx = SpringApplication.run(Application.class, args);

        DispatcherServlet dispatcherServlet = (DispatcherServlet)ctx.getBean("dispatcherServlet");
        dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);
    }
}

Result when I use non defined URL

{
    "errorCode": "custom_404",
    "errorMessage": "message for 404 error code"
}

UPDATE: In case you configure your SpringBoot application using application.properties then you need to add the following properties instead of configuring DispatcherServlet in main method (thanks to @mengchengfeng):

spring.mvc.throw-exception-if-no-handler-found=true
spring.resources.add-mappings=false