Internationalization in Spring boot MVC project

Question

application.properties

spring.messages.basename=i18n/messages

/home/michael/IdeaProjects/adsmanager/application/src/main/resources/i18n/messages_de_DE.properties

greeting=Willkommen!

/home/michael/IdeaProjects/adsmanager/application/src/main/resources/i18n/messages_en_US.properties

greeting=Welcome!

GeneralConfig.java

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
import org.springframework.web.servlet.i18n.SessionLocaleResolver;

import java.util.Locale;


    @Configuration
    public class GeneralConfig implements WebMvcConfigurer {
        @Bean
        public LocaleResolver localeResolver() {
            SessionLocaleResolver sessionLocaleResolver = new SessionLocaleResolver();
            sessionLocaleResolver.setDefaultLocale(Locale.US);
            return sessionLocaleResolver;
        }
    
        @Bean
        public LocaleChangeInterceptor localeChangeInterceptor() {
            LocaleChangeInterceptor lci = new LocaleChangeInterceptor();
            lci.setParamName("lang");
            return lci;
        }
    
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
            registry.addInterceptor(localeChangeInterceptor());
        }
    
    }

home.html

<div th:text="#{greeting}"></div>

http://localhost:8080/

??greeting_en_US??

http://localhost:8080/?lang=de_DE

??greeting_de_DE??

Incidentally, I tried to place messages properties to the resources folder directly and remove the basename annotation from application.properties. The same result.

How can I solve this problem?

Answer 1

Your application should extends WebMvcConfigurerAdapter

@Configuration
public class GeneralConfig implements WebMvcConfigurerAdapter {
    
    @Bean
    public LocaleResolver localeResolver() {
        SessionLocaleResolver sessionLocaleResolver = new SessionLocaleResolver();
        sessionLocaleResolver.setDefaultLocale(Locale.US);
        return sessionLocaleResolver;
    }

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

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