uni.ownloadFile下载下来的文件没有后缀名

let filepathss = plus.io.convertLocalFileSystemURL(data.tempFilePath);
							plus.io.resolveLocalFileSystemURL(filepathss,function(entry){
								const tempFileName = entry.name;
								entry.getParent(function (parentDicEntry) {
									console.log(parentDicEntry.fullPath)
									entry.moveTo({ fullPath: parentDicEntry.fullPath+'/'},`学生.xlsx`,function (newFile) {
										uni.openDocument({
											fileType: 'xlsx',
											filePath: newFile.fullPath,
											success: function (res2) {
												console.log('打开文档成功');
											},
											fail: function (err) {
												if(err.errCode == 1 || err.code == 1){
													uni.showToast({
														title: `未找到能打开xlsx类型文件的手机应用`,
														icon: 'none'
													})
												}
												console.log(err)
											}
										});
									},function(moveError){
										uni.showToast({
											title: `已在第三方应用中打开过，请在第三方应用查看时保存`,
											icon: 'none'
										})
									})
								})
							})
						}