Points To Remember

Accept the Locale from Headers e.g

   @RequestHeader("Accept-Language") Locale locale

Step 1 : Define Beans for Internationalization

Add the files in resources/i18n folder as shown in image

Add the following to the Application class ( The main class)



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

@Bean
public ResourceBundleMessageSource messageSource() {
ResourceBundleMessageSource source = new ResourceBundleMessageSource();
source.setBasenames("i18n/messages"); // name of the resource bundle
source.setUseCodeAsDefaultMessage(true);
return source;
}


Now inject the MessageSource Bean where you want to internationalize the message. We will be doing it in the Controller.
Note : You need to define all your resouce bundles in the messageSource bean so that the application can pick them.



@RestController
public class HomeController {

@Autowired
private MessageSource messageSource;

@RequestMapping("/msg")
public String msg(@RequestHeader("Accept-Language") Locale locale){
return messageSource.getMessage("msg",null,locale);
}
}