RestTemplateSslConfig.java

@Configuration
public class RestTemplateSslConfig {

    @Bean("httpsRestTemplate")
    @Scope("singleton")
    public RestTemplate httpsRestTemplate()
            throws NoSuchAlgorithmException, KeyStoreException, KeyManagementException {

        TrustStrategy acceptingTrustStrategy = (X509Certificate[] chain, String authType) -> true;
        SSLContext sslContext = org.apache.http.ssl.SSLContexts.custom()
                .loadTrustMaterial(null, acceptingTrustStrategy)
                .build();
        SSLConnectionSocketFactory csf = new SSLConnectionSocketFactory(sslContext);
        CloseableHttpClient httpClient = HttpClients.custom()
                .setSSLSocketFactory(csf)
                .build();
        HttpComponentsClientHttpRequestFactory requestFactory
                = new HttpComponentsClientHttpRequestFactory();
        requestFactory.setHttpClient(httpClient);

        return new RestTemplate(requestFactory);
    }
}