KnoteConfig.java

...
@Configuration
@EnableConfigurationProperties(KnoteProperties.class)
class KnoteConfig implements WebMvcConfigurer {

    @Autowired
    private KnoteProperties properties;

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry
                .addResourceHandler("/uploads/**")
                .addResourceLocations("file:" + properties.getUploadDir())
                .setCachePeriod(3600)
                .resourceChain(true)
                .addResolver(new PathResourceResolver());
    }

}