Pluralization issues within spring boot project

Currently I'm using Spring-boot + Thymeleaf and multiple languages. I can't find any easy way to use ICU4j with these. Essentially, as I get it, all what is need is to replace ResourceBundleMessageSource and its MessageFormat with the ICU4J variant. But I can't make it work together.

Maybe there is some examples of such projects or any other examples of pluralization functionality in Spring (such as this).

With the typical Spring Boot 2 + Thymeleaf project it can be achieved with this project and the following config:

@Configuration
public class YourConfigFile ...

@Bean
public ICUMessageSource messageSource() {
    ICUReloadableResourceBundleMessageSource messageSource = new ICUReloadableResourceBundleMessageSource();
    messageSource.setBasename("classpath:messages/messages");
    messageSource.setCacheSeconds(3600);
    messageSource.setDefaultEncoding("UTF-8");
    return messageSource;
}

You also need to add the ICU4J dependency from the maven.

In your messages.properties (messages_ru.properties in my case):

plural={0} {0, plural, one{пользователь}few{пользователя}other{пользователей}}

Using:

<span th:text="#{plural(0)}"></span>
<span th:text="#{plural(1)}"></span>
<span th:text="#{plural(2)}"></span>
<span th:text="#{plural(10)}"></span>

If you have troubles with finding messages.properties end getting errors like ??plural_ru??, check your location and names for these files messageSource.setBasename("classpath:messages/messages").