question: private String readNfcErrorMsg ( ByteBuffer reply ) throws IOException { int errorType = reply . getInt ( ) ; int errorCode = reply . getInt ( ) ; int msgLen = reply . getInt ( ) ; if ( msgLen == 0 ) { return "" ; } ByteBuffer msgBuffer = ByteBuffer . allocate ( msgLen ) ; readFully ( msgBuffer ) ; String errorMsg = new String ( msgBuffer . array ( ) , 0 , msgLen - 1 , Charsets . US_ASCII ) ; return String . format ( "NFC Error %d/%d: %s" , errorType , errorCode , errorMsg ) ; }
target:  Read NFC error from reply message.