A java file which will aide in testing certificate validation of a service.

sslTest.java

//javac 1.6.0_31
/*
  Compile:
    javac sslTest.java

  Usage (similar to telnet):
    java sslTest somehost someport
  e.g.
    java sslTest my.gitlabhost.com 443

  Successful expected output:
    Protocol is TLSv1
    Closing connection.
*/
import java.net.*;
import java.io.*;
import java.security.*;
import javax.net.ssl.*;

public class sslTest {
    public static void main(String[] args) {
        if (args.length < 2) {
            System.out.println("Usage: java sslTest somehost someport");
            return;
        }   

        int port = 0;
        if(args[1] == null){
            port = 443; // default https port
        }else{
            port = Integer.parseInt(args[1]);
        }   
        String host = args[0];

        try{
            Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
            SSLSocketFactory factory = (SSLSocketFactory) SSLSocketFactory.getDefault();

            SSLSocket socket = (SSLSocket) factory.createSocket(host, port);
            SSLSession session = socket.getSession();
            System.out.println("Protocol is " + session.getProtocol());
            // just close it
            System.out.println("Closing connection.");
            socket.close();
        }catch (IOException e) {
            System.err.println(e);
        }   
    }   
}