title: annotation & regex
body: <p>I need to do a validation of an e-mail using annotation + regex. I tried to use the following: </p>
  
  <pre><code>@NotNull
  @Pattern(regexp=".+@.+\\.[a-z]+")
  private String email;
  </code></pre>
  
  <p>However, I don't know how to print an error message when I have an incorrect e-mail address in the email field. Any ideas?</p>