gistfile1.txt

import java.io.*;
import java.net.URL;
import java.net.URLConnection;

public class ClientCertificate {
    public static void main(String[] args) throws IOException {
        System.setProperty("javax.net.ssl.keyStore", "myClientCert.p12");
        System.setProperty("javax.net.ssl.keyStorePassword", "mypassword");
        final URLConnection urlConnection = new URL("https://bizstn.bk.mufg.jp/biz/yen/dfw/Login").openConnection();
        try (InputStream is = urlConnection.getInputStream()) {

            final ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
            int data;
            while(-1 != (data = is.read())){
                byteArrayOutputStream.write(data);
            }
            System.out.println(byteArrayOutputStream.toString());
        }
    }
}