How to change content type for two different objectives in Spring Controller? - spring

Question

I am working on an API that displays JSON data and downloads CSV in one single API.
The problem is how to change Content-type of my header when I intend to download CSV file ?
Below is my code :
#RequestMapping(value = "${api.route.get.all.report}", method = RequestMethod.POST)
#PreAuthorize("hasAnyAuthority('super_admin','owner','admin')")
public ResponseEntity<?> getReportForAll(
#ApiParam("partnerId") #RequestParam(value = "partnerId", required = false) String partnerId,
#ApiParam("orgId") #RequestParam(value = "orgId", required = false) String orgId,
#ApiParam("eventId") #RequestParam(value = "eventId", required = false) String eventId,
#ApiParam("export") #RequestParam(value = "export") boolean export,
#ApiParam("Search Filter") #RequestBody SearchCriteriaDTO filterRequestDTO,
HttpServletResponse httpServletResponse) throws WazooException, IOException {
Object response = reportService.getReportsForAll(filterRequestDTO, partnerId, orgId, eventId, export,
httpServletResponse);
if (export) {
httpServletResponse.setContentType(MediaType.MULTIPART_FORM_DATA_VALUE);
httpServletResponse.setHeader("Content-Disposition", "filename=" + response);
return ResponseEntity.ok(waasAppUtils.createResponseEntityDTO(HttpStatusCodes.OK,
applicationUtility.getMessage("fetched"), response));
} else {
httpServletResponse.setContentType(MediaType.APPLICATION_JSON_UTF8_VALUE);
return ResponseEntity.ok(waasAppUtils.createResponseEntityDTO(HttpStatusCodes.OK,
applicationUtility.getMessage("fetched"), response));
}
}
If the purpose is only to display data(when JSON data is populated), then its working as expected and I am getting following Headers :
Content-Type →application/json;charset=UTF-8
Date →Wed, 14 Mar 2018 12:27:07 GMT
Expires →0
Here is my response
{
"response_code": 200,
"response_message": null,
"response_body": [
{
"name": "",
"totalCharges": {
"platformCharge": 0.5,
"totalCharge": 0.2,
"basicCharge": 0.3
},
"id": "5a97a5930467kf42f6a2eof1"
},
All good till this point. Now the problem is, when I wish to download CSV(export flag set to true), it returns simply the file name in response body :
{
"response_code": 200,
"response_message": null,
"response_body": "/home/reports/Report_Wed Mar 14 12:26:56 UTC 2018.csv"
}
and the content-type is still displaying me "application/json;charset=UTF-8"
How can i change the content type when the flag is set to be true and display data accordingly ???

Answer 1

If you want to return just file in case of export, try this out:
...
if (export) {
return ResponseEntity
.ok()
.contentType(MediaType.parseMediaType("text/csv"))
.header("Content-Disposition", "filename=" + fileName)
.body(<put your file content here as byte array>);
}
...