Encoded slash (%2F) with Spring RequestMapping path param gives HTTP 400

for spring-boot, the following did the trick

@SpringBootApplication
public class Application extends WebMvcConfigurerAdapter {

    public static void main(String[] args) throws Exception {
        System.setProperty("org.apache.tomcat.util.buf.UDecoder.ALLOW_ENCODED_SLASH", "true");
        SpringApplication.run(Application.class, args);
    }

    @Override
    public void configurePathMatch(PathMatchConfigurer configurer) {
        UrlPathHelper urlPathHelper = new UrlPathHelper();
        urlPathHelper.setUrlDecode(false);
        configurer.setUrlPathHelper(urlPathHelper);
    }

}

This could be your answer: urlencoded Forward slash is breaking URL

I would suggest not putting that in the path, move it to a request param instead.

Work around:

You could change the RequestMapping to

@RequestMapping(value = "/ws/stuff/lookup/resourceId/**", method = RequestMethod.GET) 

and then parse the path variables manually from the request object.