Add SSLSocketClient in Java

Note this doesn't add alpn (same as openssl). See here https://docs.oracle.com/javase/8/docs/api/javax/net/ssl/SSLSocket.html
if you want to add that.

This code is NOT GPLv2! It was taken from the Oracle web site which didn't list any license
(https://docs.oracle.com/javase/10/security/sample-code-illustrating-secure-socket-connection-client-and-server.htm).

etc/SSLSocketClient.java

@@ -0,0 +1,87 @@
+import java.net.*;
+import java.io.*;
+import javax.net.ssl.*;
+
+/*  java SSLSocketClient
+ *  https://docs.oracle.com/javase/10/security/sample-code-illustrating-secure-socket-connection-client-and-server.htm
+ */
+
+/*
+ * This example demostrates how to use a SSLSocket as client to
+ * send a HTTP request and get response from an HTTPS server.
+ * It assumes that the client is not behind a firewall
+ */
+
+public class SSLSocketClient {
+
+    public static void main(String[] args) throws Exception {
+        String host=args[0];
+
+        if ( args == null || args.length == 0 || host.trim().isEmpty() ) {
+            System.out.println("You need to supply a valid hostname");
+        } else {
+            try {
+                SSLSocketFactory factory =
+                    (SSLSocketFactory)SSLSocketFactory.getDefault();
+                SSLSocket socket =
+                    (SSLSocket)factory.createSocket(host, 443);
+
+                /*
+                * send http request
+                *
+                * Before any application data is sent or received, the
+                * SSL socket will do SSL handshaking first to set up
+                * the security attributes.
+                *
+                * SSL handshaking can be initiated by either flushing data
+                * down the pipe, or by starting the handshaking by hand.
+                *
+                * Handshaking is started manually in this example because
+                * PrintWriter catches all IOExceptions (including
+                * SSLExceptions), sets an internal error flag, and then
+                * returns without rethrowing the exception.
+                *
+                * Unfortunately, this means any error messages are lost,
+                * which caused lots of confusion for others using this
+                * code.  The only way to tell there was an error is to call
+                * PrintWriter.checkError().
+                */
+                socket.startHandshake();
+
+                PrintWriter out = new PrintWriter(
+                                    new BufferedWriter(
+                                    new OutputStreamWriter(
+                                    socket.getOutputStream())));
+
+                out.println("GET / HTTP/1.1");
+                out.println("Host: " + host);
+                out.println("Connection: close");
+                out.println();
+                out.flush();
+
+                /*
+                * Make sure there were no surprises
+                */
+                if (out.checkError())
+                    System.out.println(
+                        "SSLSocketClient:  java.io.PrintWriter error");
+
+                /* read response */
+                BufferedReader in = new BufferedReader(
+                                        new InputStreamReader(
+                                        socket.getInputStream()));
+
+                String inputLine;
+                while ((inputLine = in.readLine()) != null)
+                    System.out.println(inputLine);
+
+                in.close();
+                out.close();
+                socket.close();
+
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}