메시지국제화 챕터 질문

package hello.config;

import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
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.CookieLocaleResolver;
import org.springframework.web.servlet.i18n.FixedLocaleResolver;
import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
import org.springframework.web.servlet.i18n.SessionLocaleResolver;

import java.util.Locale;

@Configuration
public class LocalConfig implements WebMvcConfigurer {

    @Bean
    public LocaleResolver localeResolver() {
        return new SessionLocaleResolver();
    }

    @Bean
    public MessageSource messageSource() {
        ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
        messageSource.setDefaultEncoding("UTF-8");
        messageSource.setBasenames("messages", "error");

        return messageSource;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        LocaleChangeInterceptor localeChangeInterceptor = new LocaleChangeInterceptor();
        localeChangeInterceptor.setParamName("locale");
        registry.addInterceptor(localeChangeInterceptor);
    }
}

따로 LocalConfig 클래스를 구현했고

<a href="?locale=ko">한국어</a> | <a href="?locale=en">English</a><br/>

각 폼마다 한국어랑 영어를 선택할수 있게했는데 언어가 변경이안됩니다.messages 프로퍼티스도 다 적용했고 form에서 타임리프로 적용도했습니다.

크롬설정으로 언어 우선순위를 바뀌면 바뀌는데 . 이방식으로는 변하지않아서요