title: @NotNull annotation is not working in spring boot
body: <p>I am new to Spring Boot and I have this problem.</p>
  <p><a href="https://i.stack.imgur.com/ornIS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ornIS.png" alt="enter image description here" /></a></p>
  <p>and I still get 200 OK even though I don't provide &quot;data&quot;</p>
  <p><a href="https://i.stack.imgur.com/zjrCE.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zjrCE.png" alt="enter image description here" /></a></p>
  <p>Why do you think this is happening?</p>
  <p>Any Help is appreciated.</p>
  <p>Best</p>