Update FcmConfig.java

Author: JungYoonShin

src/main/java/org/terning/user/config/FcmConfig.java

@@ -22,15 +22,20 @@ public class FcmConfig {
     @PostConstruct
     public void init() {
         try {
-            String serviceKeyJson = fcmProperties.getServiceKey();
-
-            try (ByteArrayInputStream serviceAccountStream =
-                         new ByteArrayInputStream(serviceKeyJson.getBytes(Encoding.UTF_8))) {
-
+            String base64EncodedServiceKey = fcmProperties.getServiceKey();
+    
+            if (base64EncodedServiceKey == null || base64EncodedServiceKey.isBlank()) {
+                throw new IllegalStateException("Firebase service key is missing or blank.");
+            }
+    
+            byte[] decoded = java.util.Base64.getDecoder().decode(base64EncodedServiceKey);
+    
+            try (ByteArrayInputStream serviceAccountStream = new ByteArrayInputStream(decoded)) {
+    
                 FirebaseOptions options = FirebaseOptions.builder()
                         .setCredentials(GoogleCredentials.fromStream(serviceAccountStream))
                         .build();
-
+    
                 if (FirebaseApp.getApps().isEmpty()) {
                     FirebaseApp.initializeApp(options);
                     log.info(FcmLogMessages.INIT_SUCCESS);
@@ -40,4 +45,4 @@ public void init() {
             throw new RuntimeException(FcmLogMessages.INIT_FAILED + e.getMessage(), e);
         }
     }
-}
+}