WebConfig.java

package org.springframework.issues.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@EnableWebMvc
@ComponentScan(basePackages="org.springframework.issues")
@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {

	@Override
	public void addResourceHandlers(ResourceHandlerRegistry registry) {
		registry.addResourceHandler("/static/**")
				.addResourceLocations("/static/");
	}

	@Override
	public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
		// or MediaType.TEXT_PLAIN ?
		configurer.mediaType("yaml", new MediaType("application","swagger-v20+yaml"));
	}
}