下载文件需要在Header添加中加Authorization放token时可用

function downFile(id,name,extend){

    var url = ip+"/archive/downloadFile";

              var xhr = new XMLHttpRequest();
              xhr.open("get", url+"?id="+id, true);
              xhr.responseType = "blob";
              xhr.setRequestHeader('Authorization',"Bearer " + store.get("access_token"));
              xhr.onload = function () {

                  if (this.status == 200) {
                      var blob = this.response;
                      var reader = new FileReader();
                      reader.readAsDataURL(blob);
                      reader.onload = function (e) {
                          var a = document.createElement('a');
                          a.download = name+"."+extend;
                          a.href = e.target.result;
                          document.body.appendChild(a);
                          a.click();
                          document.body.removeChild(a);
                      }
                  }
              };
              xhr.send();

  }