Java Rest Client supporting SSL and self-signed certificate

RestClient.java

    protected String getData(String... params)
    {
        // Removed params checks
        try 
        {
            if (!params[0].isEmpty()) 
            {
                m_restUrl += "?date=" + params[0];
            }

            URL url = new URL(m_restUrl);
            SSLContext sslContext = getSSLContext();
            HttpsURLConnection urlConnection = (HttpsURLConnection)url.openConnection();
            urlConnection.setSSLSocketFactory(sslContext.getSocketFactory());

            InputStream inputStream = new BufferedInputStream(urlConnection.getInputStream());
            try (ByteArrayOutputStream result = new ByteArrayOutputStream()) 
            {
                byte[] buffer = new byte[1024];
                int length;
                while ((length = inputStream.read(buffer)) != -1) 
                {
                    result.write(buffer, 0, length);
                }

                output = result.toString("UTF-8");
            } finally 
            {
                urlConnection.disconnect();
            }
        } catch (Exception ex) 
        {
            output = "ERROR: " + ex.getMessage();
        }  

        return output;
    }

   /**
     * If we aren't using a public CA for the SSL connection we can trust the self-signed CA
     * @return SSLContext that includes self-signed CA
     */
    private SSLContext getSSLContext()
    {
        try {
            CertificateFactory cf = CertificateFactory.getInstance("X.509");

            // Load the CA. I've included in the Assets folder
            AssetManager assetManager = m_context.getAssets();
            InputStream caInput = assetManager.open("myCA.pem");

            Certificate ca;
            try
            {
                ca = cf.generateCertificate(caInput);
            }
            finally
            {
                caInput.close();
            }

            // Create a KeyStore containing our trusted CA
            String keyStoreType = KeyStore.getDefaultType();
            KeyStore keyStore = KeyStore.getInstance(keyStoreType);
            keyStore.load(null, null);
            keyStore.setCertificateEntry("ca", ca);

            // Create a TrustManager that trusts the CAs in our KeyStore
            String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
            TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
            tmf.init(keyStore);

            // Create an SSLContext that uses our TrustManager
            SSLContext context = SSLContext.getInstance("TLS");
            context.init(null, tmf.getTrustManagers(), null);

            return context;
        }
        catch(Exception ex)
        {
            return null;
        }
    }