Concurrency of a HttpClient in a singleton

I use Spring Boot and created a service (part of Microservices Design). I have the below method,

public static HttpClient getHttpClient() throws KeyManagementException, NoSuchAlgorithmException {

        log.info("Creating Http Client...");
        final SSLConnectionSocketFactory sslConnectionSocketFactory = new SSLConnectionSocketFactory(
                new SSLContextBuilder().build());
        final PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
        connectionManager.setMaxTotal(200);
        connectionManager.setDefaultMaxPerRoute(20);

        return HttpClients.custom()
                .disableRedirectHandling()
                .setSSLSocketFactory(sslConnectionSocketFactory)
                .setConnectionManager(connectionManager)
                .build();
    }

I invoke this method multiple times, wanted to maintain only one instance and reuse it once created. Considering concurrent programming, can i use Singleton Pattern? and i see RestTemplate is pretty good approach rather than Apache Http Client as per below link,

RestTemplate vs Apache Http Client for production code in spring project

Suggestion are much appreciated.