enable set appName for external navigation API

src/main/java/io/boomerang/service/profile/LaunchpadNavigationServiceImpl.java

@@ -20,6 +20,7 @@
 import io.boomerang.model.profile.Navigation;
 import io.boomerang.model.profile.NavigationResponse;
 import io.boomerang.model.profile.Platform;
+import io.boomerang.mongo.model.Config;
 import io.boomerang.mongo.service.FlowSettingsService;
 import io.boomerang.security.model.UserToken;
 import io.boomerang.security.service.ApiTokenService;
@@ -127,16 +128,29 @@ private NavigationResponse getExternalNavigationResponse(String email) {
     NavigationResponse result = response.getBody();
     if (result != null && result.getPlatform() != null) {
       if(Strings.isBlank(result.getPlatform().getAppName())) {
-        // set default appName if the external Navigation API does NOT return appName.
-        String defaultAppName = settingsService.getConfiguration("customizations", "appName").getValue();
-        result.getPlatform().setAppName(defaultAppName);
+        // set default appName from settings if the external Navigation API does NOT return appName.
+        result.getPlatform().setAppName(this.getAppNameInSettings());
       }
-      if(!Strings.isBlank(result.getPlatform().getPlatformName())) {
-        // add | to the end of the platformName
+      if(!Strings.isBlank(result.getPlatform().getPlatformName()) 
+          && !Strings.isBlank(result.getPlatform().getAppName())) {
+        /*
+         *  add | to the end of the platformName when both platformName and appName exist. 
+         *  The UI header will display like "platformName | appName"
+         */
         result.getPlatform().setPlatformName(result.getPlatform().getPlatformName() + " |");
       }
     }
-    return response.getBody();
+    return result;
+  }
+
+  private String getAppNameInSettings() {
+    try {
+      Config config = settingsService.getConfiguration("customizations", "appName");
+      return config == null ? null : config.getValue();
+    } catch (Exception e) {
+    }
+    // return null instead of throwing exception when appName is not configured in settings.
+    return null;
   }
 
   private HttpHeaders buildHeaders(String email) {
@@ -146,4 +160,4 @@ private HttpHeaders buildHeaders(String email) {
     headers.setContentType(MediaType.APPLICATION_JSON);
     return headers;
   }
-}
+}