Spring to Ping: how to configure Spring Rest Service to use External Authorization Server PingFederate

Does anyone know how to configure a Spring Rest Service to use PingFederate as an External Authorization Server?

Asked this question before, it was closed for god knows why. But here is the answer that I found. I based this on a demo that uses Google as an external authorization server. The problem with the usual demos is that they all use the Spring Authorization Server. Here is the place to start https://arnoldgalovics.com/google-oauth-with-spring-security-as-separated-resource-server/ Then modify the GoogleAccessTokenValidator like this (below). Questions, fire away...

private HttpHeaders createHeaders(final String username, final String password){
       return new HttpHeaders() {{
             String auth = username + ":" + password;
             byte[] encodedAuth = Base64.encodeBase64( 
                auth.getBytes(Charset.forName("US-ASCII")) );
             String authHeader = "Basic " + new String( encodedAuth );
             set( "Authorization", authHeader );
          }};
    }

    
    @SuppressWarnings("unchecked")
    private Map<String, ?> getPingResponse(String accessToken) {
        
        //Ping speaks text/html
        List<HttpMessageConverter<?>> converters = restTemplate.getMessageConverters();
        for (HttpMessageConverter<?> converter : converters) {
            if (converter instanceof StringHttpMessageConverter) {
                StringHttpMessageConverter stringConverter = (StringHttpMessageConverter) converter;                
                stringConverter.setSupportedMediaTypes(ImmutableList.of(new MediaType("text", "html", StringHttpMessageConverter.DEFAULT_CHARSET)));
            }
        }       
        
        //URL
        UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(checkTokenUrl)
                .queryParam("grant_type", "urn:pingidentity.com:oauth2:grant_type:validate_bearer")
                .queryParam("token", accessToken);      
        String url =  builder.build().encode().toUri().toString();
        
        //Basic Auth (from Ping, OAuth Settings, Manage Clients
        HttpEntity<Object> requestEntity = new HttpEntity<Object>(createHeaders("my-trusted-client", "secret"));
        
        //unused Spring exchange variables
        Map<String, String> variables = ImmutableMap.of("ping does not", "use this"); //token only in queryParam above
        
        //validation call to Ping
        Map map = restTemplate.exchange(url, HttpMethod.POST, requestEntity, Map.class, variables).getBody();        
        return (Map<String, Object>) map;
    }