fileNameString = contentDisposition.substring(contentDisposition.indexOf("filename=") + 9, contentDisposition.indexOf(";", contentDisposition.indexOf("filename=") + 9));
} else if (contentDisposition.contains("filename=")) { // The file name is contained in a string beginning with `filename=` and proceeding to the end of `contentDisposition`.
fileNameString = contentDisposition.substring(contentDisposition.indexOf("filename=") + 9, contentDisposition.indexOf(";", contentDisposition.indexOf("filename=") + 9));
} else if (contentDisposition.contains("filename=")) { // The file name is contained in a string beginning with `filename=` and proceeding to the end of `contentDisposition`.