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

In springboot it is even simplier. Because of Spring autoconfiguration stuff, spring creates a bean org.springframework.boot.autoconfigure.web.servlet.WebMvcProperties. This class is annotated with @ConfigurationProperties(prefix = "spring.mvc") and therefore it will seek for properties with spring.mvc prefix.

Part from javadoc:

Annotation for externalized configuration. Add this to a class definition or a
* @Bean method in a @Configuration class if you want to bind and validate
* some external Properties (e.g. from a .properties file).

You just have to add to your i.e. application.properties file following properties:

 spring.mvc.throwExceptionIfNoHandlerFound=true
 spring.resources.add-mappings=false //this is for spring so it won't return default handler for resources that not exist

and add exception resolver as follows:

@ControllerAdvice
public class ExceptionResponseStatusHandler {
    @ExceptionHandler(NoHandlerFoundException.class)
    public ModelAndView handle404() {
        var out = new ModelAndView();
        out.setViewName("404");//you must have view named i.e. 404.html
        return out;
    }
}