404 error redirect in Spring with java config

Question

As you know, in XML, the way to configure this is:

    404
    /my-custom-page-not-fo         


        

Answer 1

A solution for Spring 5 and Thymeleaf 3.

In MyWebInitializer, enable exception throwing with setThrowExceptionIfNoHandlerFound(). We need to do casting to DispatcherServlet.

@Configuration
public class MyWebInitializer extends
        AbstractAnnotationConfigDispatcherServletInitializer {

        ...

        @Override
        protected FrameworkServlet createDispatcherServlet(WebApplicationContext servletAppContext) {
            var dispatcher = (DispatcherServlet) super.createDispatcherServlet(servletAppContext);
            dispatcher.setThrowExceptionIfNoHandlerFound(true);
            return dispatcher;
        }
    }

Create a controller advice with @ControllerAdvice and add error message to the ModealAndView.

@ControllerAdvice
public class ControllerAdvisor {

    @ExceptionHandler(NoHandlerFoundException.class)
    public ModelAndView handle(Exception ex) {

        var mv = new ModelAndView();
        mv.addObject("message", ex.getMessage());
        mv.setViewName("error/404");

        return mv;
    }
}

Create 404 error template, which displays the error message. Based on my configuration, the file is src/main/resources/templates/error/404.html.

    
    
    



404 - resource not found


    

For completeness, I add the Thymeleaf resolver configuration. We configure the Thymeleaf templates to be in templates directory on the classpath.

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"com.zetcode"})
public class WebConfig implements WebMvcConfigurer {

    @Autowired
    private ApplicationContext applicationContext;

    ...

    @Bean
    public SpringResourceTemplateResolver templateResolver() {

        var templateResolver = new SpringResourceTemplateResolver();

        templateResolver.setApplicationContext(applicationContext);
        templateResolver.setPrefix("classpath:/templates/");
        templateResolver.setSuffix(".html");

        return templateResolver;
    }
    ...
}