fix PAD record log

internal/app/ami/action/index.go

@@ -181,7 +181,11 @@ func HandleAMI(event map[string]string) {
 
 					if strings.Contains(event["FILENAME"], "PAD") {
 						_, caller, callee := utils.GetPadInfo(event["FILENAME"])
-						utils.Logger.Printf("Train Information:%s , MessageType: PAD , CabNumber: %c , LocationCode: %c, Connected: %s, RecordFileName:%s", trainInfo, caller[2], caller[3], callee, DstFile)
+						if len(caller) == 4 && len(caller) > 0 {
+							utils.Logger.Printf("Train Information: CabNumber %s, MessageType: PAD , CabNumber: %c , LocationCode: %c, Connected: %s, RecordFileName:%s", trainInfo, caller[2], caller[3], callee, DstFile)
+						} else {
+							utils.Logger.Printf("Train Information: CabNumber %s, MessageType: PAD , RecordFileName:%s . Can not get caller and callee  !", trainInfo, DstFile)
+						}
 					} else if strings.Contains(event["FILENAME"], "PA") {
 						_, caller, _ := utils.GetPadInfo(event["FILENAME"])
 						utils.Logger.Printf("Train Information:%s , MessageType: PA, Caller: %s, RecordFileName: %s", trainInfo, caller, DstFile)