Pls give the content type for open a xlsx file in browser

jsp file
Excel js file

function exportExcel(tableID, filename = ''){

var downloadLink;
//var dataType = 'application/vnd.ms-excel.12'
//Response.ContentType ="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
// var dataType ="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";

var dataType = 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet';
var tableSelect = document.getElementById(tableID);
var tableHTML = tableSelect.outerHTML.replace(/ /g, '%20');

// Specify file name
filename = filename?filename:'excel_data';

// Create download link element
downloadLink = document.createElement("a");

document.body.appendChild(downloadLink);

if(navigator.msSaveOrOpenBlob){
var blob = new Blob(['\ufeff', tableHTML], {
type: dataType
});
navigator.msSaveOrOpenBlob( blob, filename);
}else{
// Create a link to the file
downloadLink.href = 'data:' + dataType + ', ' + tableHTML;

// Setting the file name
downloadLink.download = filename;

//triggering the function
downloadLink.click();

}
}

it didn't work out as for Office 2010 application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

I Hope contenttype meants MIME Type
.xlsx