Untitled

<!DOCTYPE html>
<html>
<head>
  <title>Женя лох!!1</title>
  <meta charset="utf-8">
</head>

<body>

  <script>

    var req = new XMLHttpRequest();
    var url = "http://localhost:8080/oauth/token?grant_type=password&username=IIvanov@gmail.com&password=password";

    req.open('POST', url, true);
    req.setRequestHeader('Authorization', 'Basic Y2xpZW50OnNlY3JldA==');
    req.send();

    req.addEventListener('load', function() {
      document.write(this.responseText);
    });

    req.addEventListener('error', function() {
      console.log(this.responseText);
    });

  </script>

</body>

</html>