SSLHandshakeException JAVA : client SSL call using key and certificate file

Question

I have a cert file and its key. Using these two I am able to call a given service api successfully using postman.

Now I am trying to write a client which should use these two and call the API.Before writing the java code,using openssl created a pfx file using the existing cert file and its corresponding key.After going through few of the examples over internet/stackoverflow:

private static String trustStorePath = "/Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home/jre/lib/security/cacerts";
private static final String trustStorePassword = "changeit";
private static final String keyStoreFile = "/pathTocert/mycert.pfx";
private static final String keyStorePassword = "changeit";

public static SSLSocketFactory enableSSL() {
    SSLContext context = null;
    InputStream keyInput = null, truststream = null, certInput = null;

    KeyStore trustks;
    try {

        KeyStore keyStore = KeyStore.getInstance("PKCS12");
        keyInput =  new FileInputStream(new File(keyStoreFile));


        keyStore.load(keyInput, keyStorePassword.toCharArray());
        KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance("SunX509");
        keyManagerFactory.init(keyStore, keyStorePassword.toCharArray());

        trustks = KeyStore.getInstance("JKS");
        File trustcert = new File(trustStorePath);
        truststream = new FileInputStream(trustcert);
        trustks.load(truststream, trustStorePassword.toCharArray());
        truststream.close();

        TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
        tmf.init(trustks);

        context = SSLContext.getInstance("TLS");
        context.init(keyManagerFactory.getKeyManagers(), tmf.getTrustManagers(), new SecureRandom());

        return context.getSocketFactory();

    } catch (KeyStoreException e) {

        e.printStackTrace();
    } catch (IOException e) {

        e.printStackTrace();
    } catch (NoSuchAlgorithmException e) {

        e.printStackTrace();
    } catch (CertificateException e) {

        e.printStackTrace();
    } catch (UnrecoverableKeyException e) {

        e.printStackTrace();
    } catch (KeyManagementException e) {

        e.printStackTrace();
    }
    return null;

}

And after doing it in my main method,I am setting SSLSocketFactory and making a https call :

            URL myUrl = new URL(httpsURL);
            SSLSocketFactory sslSocketFactory = enableSSL();
             HttpsURLConnection conn = (HttpsURLConnection)myUrl.openConnection();

            conn.setSSLSocketFactory(sslSocketFactory);

             InputStream is = conn.getInputStream();
             InputStreamReader isr = new InputStreamReader(is);
             BufferedReader br = new BufferedReader(isr);

             String inputLine;

                while ((inputLine = br.readLine()) != null) {
                    System.out.println(inputLine);
                }

                br.close();

I am new to Java security library and I am stuck with

javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: No trusted certificate found

I have already tried few of the steps like installing the pfx in cacerts of JDK or changing the code as given on URL

How to connect to a secure website using SSL in Java with a pkcs12 file?

But none has worked so far for me.I will appreciate any help on this.Please write in comment if more info is needed is needed.