title: how to secure zip file upload?
body: <p>I've a project in netbeans which my employer wants me to add a bulk file upload.
  The requirement was ,the user will put a csv file and some images in a folder in client side. on the file upload page he will choose the csv file and i have to upload the images in the folder along with the csv.
  After a short research i found that the client side file location and details can't be accessed from the server side so instead of uploading a single file and  the contents in the folder which it belong, the user will zip all the files and upload the zip file .
  Now i'm conserned about the security risks of uploading a zip file.</p>
  
  <ol>
  <li>What all are the measures should i take to prevent the upload of malecious scripts and files along with the zip?</li>
  <li>Is it possible to validate the file content before it reach the server ?</li>
  <li>Is it possible to validate it securely even after it reached the server side ?</li>
  </ol>