title: How to check if only one '@' symbol in email address using regex in java?
body: <p>I am trying to create a regex in java to validate the email address. It should contain one uppercase one lowercase one digit only one @ symbol followed by '.'.So far i could only create this,</p>
  
  <pre><code>^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*@)(?=.*\.).+$
  </code></pre>
  
  <p>scenarios like these</p>
  
  <p>abC.8@gmailcom this address should return false</p>
  
  <p>abC8@@gmail.com this also should return  false</p>
  
  <p>But the above regex returns true for all these scenarios.Could anyone help me correct this regex?</p>