Load contextual config in spring boot

Question

I have a spring boot app which uses country wise config files. The structure of the config files is same but values are different for different countries.

I have created a directory for each country in resources directory and placed that country's config file there.

Based on the country code passed in request parameters, I want to use the corresponding config file. What's the spring boot idiomatic way to achieve this (Apart from manually loading the yaml config files using something like snakeyaml)?

Thanks

Answer 1

You can acheive by creating bean for MessageSource,LocaleResolver and LocaleChangeInterceptor bean and then add LocaleChangeInterceptor to InterceptorRegistry like this:

@Configuration
    public class CountryConfig extends WebMvcConfigurerAdapter{

        @Bean
        public MessageSource messageSource() {
            ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
            messageSource.setBasenames("classpath:country-conf/country");
            messageSource.setUseCodeAsDefaultMessage(true);
            messageSource.setDefaultEncoding("UTF-8");
            messageSource.setCacheSeconds(3600);
            return messageSource;
        }

        @Bean
        public LocaleResolver localeResolver() {
            SessionLocaleResolver slr = new SessionLocaleResolver();
            slr.setDefaultLocale(Locale.US);
            return slr;
        }

        @Bean
        public LocaleChangeInterceptor localeChangeInterceptor() {
            LocaleChangeInterceptor lci = new LocaleChangeInterceptor();
            lci.setParamName("country");
            return lci;
        }

        @Override
        public void addInterceptors(InterceptorRegistry registry) {
            registry.addInterceptor(localeChangeInterceptor());
        }
    }

And then create a folder-country-conf in resources folder . Inside this folder create properties file which will have your configuration. Ex:

country.properties (Default)

country.name=United states

country_fr.properties

country.name=France

country.properties is the default properties if no country is sent in parameter and if you send country=fr in parameter then it will look for country_fr.properties file.

Now create a service that will get value from these properties file based on country parameter

@Service
public class CountryService {

    @Autowired
    private MessageSource messageSource;

    public String getMessage(String code) {
        Locale locale = LocaleContextHolder.getLocale();
        return this.messageSource.getMessage(code, null, locale);
    }
}

To test this autowire country service

@Autowired
CountryService countryService;

And then call getMessage method

countryService.getMessage("country.name");