Java Android Developing "Failure In SSL Library, Usually A Protocol"

I'm programming an Application just for testing with Android Studio. I want to Request a Server with POST params which are in the string: (strings[0]). But I always get this Excep

Solution 1:

[...]
                byte[] postData = strings[0].getBytes(StandardCharsets.UTF_8);
                int postDataLength = postData.length;

                URL url = new URL("https://example.com");
  // The url has to be set to an international variable

                new Thread(new Runnable() {
                     public void run() {

                        // The url has to be fetched from an international variable
                        HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();

                //
                        conn.setDoOutput(true);
                        conn.setInstanceFollowRedirects(false);
                        conn.setRequestMethod("POST");
                        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                        conn.setRequestProperty("charset", "utf-8");
                        conn.setRequestProperty("Content-Length", Integer.toString(postDataLength));
                        conn.setUseCaches(false);

                        //
                        // TLSv1 | TLSv1.1 | TLSv1.2
                        SSLContext sc = SSLContext.getInstance("TLSv1.2");
                        sc.init(null, null, new java.security.SecureRandom());
                        sc.getProtocol();
                        sc.getSupportedSSLParameters();
                        sc.getDefaultSSLParameters();
                        SSLEngine engine = sc.createSSLEngine();


                        conn.setSSLSocketFactory(sc.getSocketFactory());

                        conn.connect();
                      });
                    }
                }).start();

                try (final InputStream in = conn.getInputStream()) {
                    //…
                }
[...]

https://developer.android.com/guide/components/processes-and-threads