final TrustManager[] trustAllCerts = new TrustManager[]{
    new X509TrustManager() {
        @Override
        public void checkClientTrusted(java.security.cert.X509Certificate[] chain, String authType) throws CertificateException {
        }

        @Override
        public void checkServerTrusted(java.security.cert.X509Certificate[] chain, String authType) throws CertificateException {
        }

        @Override
        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
            return new X509Certificate[0];
        }
    }
};

final SSLContext sslContext = SSLContext.getInstance("SSL");
sslContext.init(null, trustAllCerts, new java.security.SecureRandom());
final SSLSocketFactory sslSocketFactory = sslContext.getSocketFactory();

final OkHttpClient client = new OkHttpClient.Builder()
    .sslSocketFactory(sslSocketFactory, (X509TrustManager) trustAllCerts[0])
    .hostnameVerifier((hostname, session) -> true).build();

String hostname = "site.com";
Request request = new Request.Builder().url("https://" + hostname)
    .build();
Response response = client.newCall(request).execute();
System.out.println("finish, response = " + response.body().string());