Unable to upload file to server

Hi, I am new to Vaadin. I am trying to make use of the “Multi-Upload” component that is present under
https://vaadin.com/elements/-/element/vaadin-upload#demos

This is my script. While uploading the file, in browser, its showing that upload is completed. But, in the server, under the path mentioned, I could not find the file… Do i need to implement any listeners or receivers to accept the file on server ?? or is automatically taken care by vaadin itself ??

(By the way, I am accessing vaadin core elements through CDN & not through Bower)

Please help

Hello World
<vaadin-upload id="RequestDemo" method="POST" target="http://102.254.25.12:8080/FirstProject">
</vaadin-upload>

Please help…Anybody ??