Unable to download Excel spreadsheet with outputstream data from backend - angularjs

Question

The REST method to return outputStream data to download an Excel spreadsheet:
#RequestMapping(value = "/downloadxls", method = RequestMethod.GET)
public #ResponseBody void getRecordsAndExportExcel(#RequestParam("search_param") String students, HttpServletResponse response) {
response.setContentType("application/vnd.ms-excel");
Workbook hssfWorkbook = exportExcelService.getExcelStudents(students);
try {
OutputStream out = response.getOutputStream();
hssfWorkbook.write(out);
out.flush();
out.close();
} catch (IOException e) {
logger.error("Error exporting to excel:" + e);
}
}
I am getting the data as bytes, but in Angular I am trying to present it as an Excel spreadsheet; but it won't download. I am doing this for the conversion:
var blob = new Blob([result.data], {type : 'application/vnd.openxmlformats-officedocument.presentationml.presentation;charset=UTF-8'});
FileSaver.saveAs(blob, "MyData.xls");
The request and response headers:
Access-Control-Allow-Headers:x-requested-with, content-type
Access-Control-Allow-Methods:GET OPTIONS
Access-Control-Allow-Origin:*
Access-Control-Max-Age:3600
Content-Type:application/vnd.ms-excel;charset=UTF-8
Server:Apache-Coyote/1.1
Transfer-Encoding:chunked
X-Application-Context:application:8080
Request Headers
Accept:application/json, text/plain, */*
Accept-Encoding:gzip, deflate, sdch
Accept-Language:en-US,en;q=0.8,ms;q=0.6
Connection:keep-alive
Host:localhost:8080
Origin:http://localhost:9000
Referer:http://localhost:9000/
I am making a GET-call from frontend using Angular and calling backend to download the data as an Excel spreadsheet, but it is not able to convert the output stream to blob/excel. How can I present an Excel spreadsheet as download?

Answer 1

The way I would present an excel sheet in my application is to return the path+filename of the excel sheet to show and then open the link using angular in a new tab.
In the service class
ExportExcel response = new ExportExcel();
response.setPath(excelPath);
return response;
Controller class
Response response = excelService.generateExcel();
return new ResponseEntity<>(response, HttpStatus.OK);
In your angular controller:
if(response.status === 200){
var excelPath = response.data.path;
var win = window.open(excelPath, '_blank');
if (win) {
//Browser has allowed it to be opened
win.focus();
} else {
//Browser has blocked it
swal(
"Error!",
'Please allow popups for this website',
"error"
);
}
}
Try and see if this works.