[URGENT] Fix locale if folder not exist on file path

smp-webapp/src/main/java/eu/europa/ec/edelivery/smp/ui/external/LocaleController.java

 package eu.europa.ec.edelivery.smp.ui.external;
 
 import eu.europa.ec.edelivery.smp.i18n.SMPLocale;
+import eu.europa.ec.edelivery.smp.logging.SMPLogger;
+import eu.europa.ec.edelivery.smp.logging.SMPLoggerFactory;
 import eu.europa.ec.edelivery.smp.services.SMPLocaleService;
+import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.FileSystemResource;
+import org.springframework.core.io.Resource;
 import org.springframework.util.MimeTypeUtils;
 import org.springframework.web.bind.annotation.*;
 
+import java.nio.file.Path;
+
 import static eu.europa.ec.edelivery.smp.ui.ResourceConstants.CONTEXT_PATH_PUBLIC_LOCALE;
 
 /**
  * Provides support for returning locale files required by the ngx-translation Angular library.
  *
- * @since 5.1
  * @author Sebastian-Ion TINCU
+ * @since 5.1
  */
 @RestController
 @RequestMapping(value = CONTEXT_PATH_PUBLIC_LOCALE)
 public class LocaleController {
-
+    private static final SMPLogger LOG = SMPLoggerFactory.getLogger(LocaleController.class);
+    private static final String DEFAULT_LOCALE_RESOURCE = "/META-INF/resources/ui/assets/i18n/en.json";
     private final SMPLocaleService smpLocaleService;
 
     public LocaleController(SMPLocaleService smpLocaleService) {
@@ -26,7 +33,21 @@ public class LocaleController {
 
     @GetMapping(value = "/{code}", produces = MimeTypeUtils.APPLICATION_JSON_VALUE)
     @ResponseBody
-    public FileSystemResource getLocale(@PathVariable("code") String code) {
-        return new FileSystemResource(smpLocaleService.getLocaleFile(SMPLocale.fromCodeDefaultingToEnglish(code)));
+    public Resource getLocale(@PathVariable("code") String code) {
+        Path langResourcePath = smpLocaleService.getLocaleFile(SMPLocale.fromCodeDefaultingToEnglish(code));
+        if (langResourcePath.toFile().exists()) {
+            LOG.debug("Returning locale file [{}]", langResourcePath.toAbsolutePath());
+            return new FileSystemResource(langResourcePath);
+        } else {
+            LOG.warn("Locale file [{}] does not exist. Return default translation!", langResourcePath.toAbsolutePath());
+
+            ClassPathResource defResource = new ClassPathResource(DEFAULT_LOCALE_RESOURCE);
+            if (defResource.exists()) {
+                return defResource;
+            } else {
+                LOG.error("Default locale file [{}] does not exist in classpath!", DEFAULT_LOCALE_RESOURCE);
+                return null;
+            }
+        }
     }
 }