curl -X POST -vu clientapp:123456 http://localhost:8080/oauth/token -H "Accept: application/json" -d "password=spring&username=roy&grant_type=password&scope=read%20write&client_secret=123456&client_id=clientapp"

{"access_token":"29c4c218-1d9a-4d2d-abe3-197bc2969679","token_type":"bearer","refresh_token":"6b7ffda7-4652-4197-b8e9-c80635eb9143","expires_in":38630,"scope":"read write"}

Handling error: InvalidClientException, Unauthorized grant type: client_credentials