是否可以在Windows-1250的AngularJs JavaScript中保存文件？

Question

I have a webbApp in AngularJs and SpringBoot API REST.
I call a API REST with a GET to retrieve a flow of text-data and try to save it in a file with charset WINDOWS-1250.

Scenario :
1) AngularsJs client do a get to the API REST
2) API REST read a database, prepare datas and return the result in the body of the response
3) AngularsJS client save the result in a file with charset WINDOWS-1250.

So, in the third part, i save the file with FileSaver.saveAs but the file is always in UTF-8 Charset. Even if i try to set the charset in Windows-1250.

Someone may help me ?

Angular Test Script:

$http({method:'GET',   
       url: $scope.url + "/cmpcode/" + this.demand.company + "/pcmcode/" + this.demand.pcmcode + "/prlcode/" + this.demand.prlcode +  "/user/" + this.demand.user,  
       responseType : "blob" ,  
       headers:{'X-Auth-Token': sessionService.getLogonDatas.token}})  
.then(function(response) {  
    $scope.showErrorAlert = false;  
    var data = new Blob([response.data], { type: 'text/plain; charset=Windows-1250' });  
    FileSaver.saveAs(data, "MyFile.test");  
    $scope.showSuccessAlert = true;},  
function(rejection) {  
    $scope.showSuccessAlert = false;  
    if (rejection.status === 406){$scope.message.code = "NO_ROWS";}  
    $scope.showErrorAlert = true;});   
};  

SpringBoot Test APIREST:

public void getPaymentNationalFile(HttpServletResponse response,
                                       @PathVariable("cmpcode") @Length(max = 12) @NotNull String companyCode,
                                       @PathVariable("pcmcode") @Length(max = 12) @NotNull String pcmcode,
                                       @PathVariable("prlcode") @Length(max = 12) @NotNull String prlcode,
                                       @PathVariable("user") @Length(max = 12) @NotNull String user,
{
//Without Try & Catch
PaymentNationalParam paymentNationalParam = new PaymentNationalParam(companyCode, pcmcode, prlcode, user);  
paymentNationalData = paymentNationalService.GetFilePaymentNational(paymentNationalParam);  
response.setContentType("text/plain;charset=" + paymentNationalData.getCharacterEncoding());  //Here "Windows-1250"
int longueur = 0 ;
byte[] buffer = null;
ServletOutputStream servletOutputStream = response.getOutputStream();
for (String string : paymentNationalData.prepareLignePaymentToWrite()) 
{
    buffer = (string + "\n").getBytes() ;
    longueur += buffer.length;
    servletOutputStream.write(buffer , 0, buffer.length);
}
response.setContentLength(longueur);
servletOutputStream.flush();
}

API Response (extract)

Header :
Content-Type : text/plain;charset=windows-1250
Transfer-Encoding : chunked
X-Content-Type-Options : nosniff

Body extract -> line 1 and 2 of the response (more lines): 110,20170626,2594917,10500086,0,"29105000861000002274422993","16105010701000000101025518","NORAUTO POLSKA SP ZOO|UL. JUBILERSKA 10||04190 WARSZAWA","AUTOLAND
43-25|MICKIEWICZA 28| 0|43-250 PAWĹOWICE",0,10501070,"114024","","","51",""

110,20170626,70725,10500086,0,"29105000861000002274422993","58103015080000000502563009","NORAUTO POLSKA SP ZOO|UL. JUBILERSKA 10||04190 WARSZAWA","BOSCH ROBERT SP02-23|JUTRZENKI 105| 0|02-231 WARSZAWA",0,10301508,"114025","","","51",""

Answer 1

I found a way but i don't know if it's a good.

So, in the Java part, my response is a octet-stream and put this in Content-type header.

response.setContentType("application/octet-stream;charset=" + paymentNationalData.getCharacterEncoding());

and in the AngularsJs part, save the file with the Content-type Header

var data = new Blob([response.data],{type: response.headers('Content-Type')}); 
FileSaver.saveAs(data, response.headers('content-filename'));

and work !