WebClient vs RestTemplate
As per spring 5:
WebClient is an interface representing the main entry point for performing web requests.
It has been created as a part of the Spring Web Reactive module and will be replacing the classic RestTemplate in these scenarios. The new client is a reactive, non-blocking solution that works over the HTTP/1.1 protocol
Does that mean, we need to recode for the old applications using RestTemplate if we want to upgrade to Spring 5?
Or there is some workaround to work with RestTemplate in Spring 5?
Answer
No, RestTemplate will continue to exist(atleast for now). You don't have to replace it with WebClient.
One of the main difference is RestTemplate is synchronous and blocking. i.e when you do a rest call you need to wait till the response comes back to proceed further.
But WebClient is complete opposite of this. The caller need not wait till response comes back. Instead he will be notified when there is a response.
If you need such a functionality, then yes you need to replace your Resttemplate with WebClient.
You can infact achieve Rest template like synchronous processing in webclient using .block(). But the other way is not possible.
EDIT:
The RestTemplate will be deprecated in a future version(> 5.0) and will not have major new features added going forward