Non-ASCII symbols in path variable of Spring MVC application on embedded Tomcat server setup using Spring Boot

Question

I am building a service using Spring MVC set up using Spring Boot where I want to be able to have arbitrary unicode characters in the URLs.

By looking around the web I end up with

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Main {
    public static void main(String... args) throws Exception {
        SpringApplication.run(Main.class, args);
    }

    @Bean
    public Filter characterEncodingFilter() {
        CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter();
        characterEncodingFilter.setEncoding("UTF-8");
        characterEncodingFilter.setForceEncoding(true);
        return characterEncodingFilter;
    }
}

and

@Controller
public class WordController {

    @RequestMapping(value="/word/{word}", method=RequestMethod.GET)
    public String greeting(Model model, @PathVariable("word") String word) {

        System.out.println(word);

        model.addAttribute("word", word);
        return "word";
    }

}

where the template "word" just prints out the word from the model.

When I start the server and enter http://localhost:8080/word/æøå into Chrome, the text printed on the response page (and in the terminal) is

æøå

which I think I recognize as a ISO-8859-1 interpretation the Danish letters æøå when they're actually encoded in UTF-8.

Looking into Chrome's net inspector I see that it actually queries http://localhost:8080/word/%C3%A6%C3%B8%C3%A52 which indeed seems to be the URL encoding of the string in UTF-8.

Can anyone explain why Spring doesn't parse the path variable as UTF-8 despite this configuration, and how to make it?

There seems to mixed opinions on whether CharacterEncodingFilter actually solves this problem. At least, in another (non-Boot) Spring project of mine I use web.xml to register the CharacterEncodingFilter. Here it's used successfully to make POST bodies parse as UTF-8, but I coudn't make it work for path variables there either.

This answer suggests that it should be configured in Tomcat's settings. If so, how is that done on an embedded server?

Answer 1

Following the event of a brain-wave, adding the bean method

@Bean
public EmbeddedServletContainerFactory servletContainer() {
    TomcatEmbeddedServletContainerFactory factory = new TomcatEmbeddedServletContainerFactory(8080);
    factory.addConnectorCustomizers(new TomcatConnectorCustomizer() {

        @Override
        public void customize(Connector connector) {
            connector.setURIEncoding("UTF-8");
        }
    });
    return factory;
}

seems to solve the problem.

Edit

The CharacterEncodingFilter is still necessary for converting POST bodies.