title: Unable to export excel (xlsm) in angular 7 - with spring boot backend
body: <p>I have a Spring Boot controller for the export to excel feature</p>
  
  <p>The Problem is that after downloading excel says file is corrupted and never opens.
  What is wrong in the code? I know this is related to character encoding as when I download the same file via postman (using save file feature) the file opens smoothly. I see some binary characters difference if I open the postman format and angular format. </p>