feat: header Accept-Language 언어 강제하기

app/kac-app/src/main/java/kr/co/palnet/kac/app/config/WebConfig.java

@@ -0,0 +1,19 @@
+package kr.co.palnet.kac.app.config;
+
+import kr.co.palnet.kac.app.core.web.BaseAcceptHeaderLocaleResolver;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.LocaleResolver;
+import org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver;
+
+import java.util.Locale;
+
+@Configuration
+public class WebConfig {
+    @Bean
+    public LocaleResolver localeResolver() {
+        AcceptHeaderLocaleResolver localeResolver = new BaseAcceptHeaderLocaleResolver();
+        localeResolver.setDefaultLocale(Locale.KOREA);
+        return localeResolver;
+    }
+}

app/kac-app/src/main/java/kr/co/palnet/kac/app/core/web/BaseAcceptHeaderLocaleResolver.java

@@ -0,0 +1,68 @@
+package kr.co.palnet.kac.app.core.web;
+
+import jakarta.servlet.http.HttpServletRequest;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.util.StringUtils;
+import org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+
+@Slf4j
+public class BaseAcceptHeaderLocaleResolver extends AcceptHeaderLocaleResolver {
+    private final List<Locale> LOCALES = Arrays.asList(
+            new Locale("ko"),
+            new Locale("ko", "KR"),
+            new Locale("en"),
+            new Locale("en", "US")
+    );
+    private final String LOCALE_HEADER_KEY = "Accept-Language";
+
+    /**
+     * resolve locale 구성
+     *
+     * @param request the request to resolve the locale for
+     * @return
+     */
+    @Override
+    public Locale resolveLocale(HttpServletRequest request) {
+        if (!StringUtils.hasText(request.getHeader(LOCALE_HEADER_KEY))) {
+            return this.getDefaultLocale();
+        }
+        try {
+
+            Locale locale = LOCALES.stream().filter(_locale -> {
+                String defaultLocale = _locale.toString()
+                        .replaceAll("-", "")
+                        .replaceAll("_", "")
+                        .toLowerCase();
+                String headerLocale = request.getHeader(LOCALE_HEADER_KEY).toString()
+                        .replaceAll("-", "")
+                        .replaceAll("_", "")
+                        .toLowerCase();
+                return defaultLocale.equals(headerLocale);
+            }).findFirst().orElse(null);
+
+            if (locale == null) {
+                locale = LOCALES.stream()
+                        .filter(_locale -> {
+                            String language = _locale.getLanguage();
+                            return request.getHeader(LOCALE_HEADER_KEY).contains(language);
+                        })
+                        .map(_locale -> {
+                            String language = _locale.getLanguage();
+                            return new Locale(language);
+                        })
+                        .distinct()
+                        .findFirst().orElse(Locale.KOREAN);
+            }
+
+            log.info("{}, {}", request.getHeader(LOCALE_HEADER_KEY), locale);
+            return locale;
+        } catch (IllegalArgumentException e) {
+            log.warn("{}", e.getMessage());
+            return this.getDefaultLocale();
+        }
+    }
+}