Simple Mutual Authentication Client with SSL Sockets (JAVA)

client.java

//CLIENT
// this method is quick and dirty, but should get the service up and running

import javax.net.SocketFactory;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import java.io.IOException;
import java.io.OutputStreamWriter;

public class Client {

    public static void main (String[] args) throws IOException {

        try {

            // here I set my java keystore, note that these settings are GLOBAL
            System.setProperty("javax.net.ssl.keyStore", "testKeyStore.keystore");
            System.setProperty("javax.net.ssl.keyStorePassword", "password");

            // The trust store represents the certificates I trust, If I used a certificate signed by a certificate authority(CA),
            // then I would use the default java trust store. The default trust store supports most CAs. However, in this intsance, I
            // am using a self signed localhost certificate, so I will supply my own trust store, identical to my keystore.
            System.setProperty("javax.net.ssl.trustStore", "testKeyStore.keystore");
            System.setProperty("javax.net.ssl.trustStorePassword", "password");


            SocketFactory factory =  SSLSocketFactory.getDefault();

            String hostname = "localhost";
            int port = 8000;
            SSLSocket socket = (SSLSocket) factory.createSocket(hostname, port);

            // this should be true by default
            socket.setUseClientMode(true);

            // enable all cipher suites
            String[] supported = socket.getSupportedCipherSuites();
            socket.setEnabledCipherSuites(supported);

            try (OutputStreamWriter writer = new OutputStreamWriter(socket.getOutputStream(), "UTF-8")) {
                writer.write("Hello World");
                writer.flush();
            }
        }
        catch (IOException e) {
            //please throw better errors than this :)
            throw new RuntimeException();
        }

    }

}

howToTest.txt

A quick way to test this client is to use openssl's s_server tool. 
Below is an example command:

openssl s_server -Verify 1 -cert server.crt -key server.key -accept 8000

This command runs a ssl server on port 8000.The -Verify command signifies 
I am looking to recieve a certificate chain from the client of depth 1. 
The certificate and key that I supply are the same ones used in my clients java keystore.
In this example I only use one certificate and one key for both my server and client.