HTTPS和SSL的安全性

Question

我开发了一个Android应用程序，我访问一个服务器URL来访问一个xml文件。在该服务器中，我们部署了一个SelfSigned SSL服务器证书。
我试过这段代码

//我的代码：             我的代码如下：

        CertificateFactory cf = CertificateFactory.getInstance("X.509");

        InputStream caInput = this.getResources().openRawResource(R.raw.server2); //server2 is the server2.crt Certificate file
        Certificate ca;
        try {
            ca = cf.generateCertificate(caInput);
            System.out.println("ca=" + ((X509Certificate) ca).getSubjectDN());
        } finally {
            caInput.close();
        }

        // Create a KeyStore containing our trusted CAs
        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);

        // Tell the URLConnection to use a SocketFactory from our SSLContext
        HttpsURLConnection urlConnection =
                (HttpsURLConnection)url.openConnection();
        urlConnection.setSSLSocketFactory(context.getSocketFactory());
        InputStream in = urlConnection.getInputStream();

但我得到“javax.net.ssl.SSLHandshakeException：Handshake failed”Error.PLease帮助我如何访问该URL？