hal/elemento

I use to do this approach https://blog.jayway.com/2017/07/13/open-pdf-downloaded-api-javascript/

showFile(blob){
  // It is necessary to create a new blob object with mime-type explicitly set
  // otherwise only Chrome works like it should
  var newBlob = new Blob([blob], {type: "application/pdf"})

  // IE doesn't allow using a blob object directly as link href
  // instead it is necessary to use msSaveOrOpenBlob
  if (window.navigator && window.navigator.msSaveOrOpenBlob) {
    window.navigator.msSaveOrOpenBlob(newBlob);
    return;
  } 

  // For other browsers: 
  // Create a link pointing to the ObjectURL containing the blob.
  const data = window.URL.createObjectURL(newBlob);
  var link = document.createElement('a');
  link.href = data;
  link.download="file.pdf";
  link.click();
  setTimeout(function(){
    // For Firefox it is necessary to delay revoking the ObjectURL
    window.URL.revokeObjectURL(data);
  }, 100);
}

fetch([url to fetch], {[options setting custom http-headers]})
.then(r => r.blob())
.then(showFile)

but it is no longer possible
My current impl:

public class BlobDownload {

    private BlobDownload() {
    }

    public static <T> void downloadBlob(T data, String contentType, String fileName) {
        BlobPropertyBag blobPropertyBag = BlobPropertyBag.create();
        blobPropertyBag.setType(contentType);
        Blob blob = new Blob(new Blob.ConstructorBlobPartsArrayUnionType[]{Blob.ConstructorBlobPartsArrayUnionType.of(data)}, blobPropertyBag);
        downloadBlob(blob, fileName);
    }

    public static void downloadBlob(Blob blob, String fileName) {
        String url = URL.createObjectURL(blob);
        HTMLAnchorElement anchor = a()
                .attr("href", url)
                .attr("download", fileName)
                .style("display: none;")
                .element();

        DomGlobal.document.body.appendChild(anchor);
        anchor.focus();
        anchor.remove();
        DomGlobal.setTimeout(p0 -> URL.revokeObjectURL(url), 5000);
    }
}