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 expected a 404 not found error.

I got a GlobalErrorHandler

@ControllerAdvice
public class GlobalErrorHandler extends ResponseEntityExceptionHandler {

}

There is this method in ResponseEntityExceptionHandler

protected ResponseEntity<Object> handleNoHandlerFoundException(NoHandlerFoundException ex, HttpHeaders headers,
                                                     HttpStatus status, WebRequest request) {

    return handleExceptionInternal(ex, null, headers, status, request);
}

I have marked error.whitelabel.enabled=false in my properties

What else must I do for this service to throw a 404 not found response back to clients

I referred a lot of threads and don't see this trouble faced by anybody.

This is my main application class

 @EnableAutoConfiguration // Sprint Boot Auto Configuration
@ComponentScan(basePackages = "com.xxxx")
@EnableJpaRepositories("com.xxxxxxxx") // To segregate MongoDB
                                                        // and JPA repositories.
                                                        // Otherwise not needed.
@EnableSwagger // auto generation of API docs
@SpringBootApplication
@EnableAspectJAutoProxy
@EnableConfigurationProperties

public class Application extends SpringBootServletInitializer {

    private static Class<Application> appClass = Application.class;

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(appClass).properties(getProperties());

    }

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

    @Bean
    public FilterRegistrationBean correlationHeaderFilter() {
        FilterRegistrationBean filterRegBean = new FilterRegistrationBean();
        filterRegBean.setFilter(new CorrelationHeaderFilter());
        filterRegBean.setUrlPatterns(Arrays.asList("/*"));

        return filterRegBean;
    }

    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    static Properties getProperties() {
        Properties props = new Properties();
        props.put("spring.config.location", "classpath:/");
        return props;
    }

    @Bean
    public WebMvcConfigurerAdapter webMvcConfigurerAdapter() {
        WebMvcConfigurerAdapter webMvcConfigurerAdapter = new WebMvcConfigurerAdapter() {
            @Override
            public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
                configurer.favorPathExtension(false).favorParameter(true).parameterName("media-type")
                        .ignoreAcceptHeader(false).useJaf(false).defaultContentType(MediaType.APPLICATION_JSON)
                        .mediaType("xml", MediaType.APPLICATION_XML).mediaType("json", MediaType.APPLICATION_JSON);
            }
        };
        return webMvcConfigurerAdapter;
    }

    @Bean
    public RequestMappingHandlerMapping defaultAnnotationHandlerMapping() {
        RequestMappingHandlerMapping bean = new RequestMappingHandlerMapping();
        bean.setUseSuffixPatternMatch(false);
        return bean;
    }
}

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.web.resources.add-mappings=false