java download remote certificate

In one of my project, I need a certificate from the server which provides web service over https. The server can only be visited from a unix box which cannot run firefox, IE…

The java code below can download the certificate. Note, the certificate must be signed by a trusted certification provider, like versign. Otherwise, like self signed certificate, it won’t allow you establish the connection.

URL url = new URL("https://www1.royalbank.com/");
        Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("Altaproxy.tmi.telus.com", 8080));
        HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
        con.connect();
        Certificate certs[] = con.getServerCertificates();
        for (Certificate cert : certs) {
            System.out.println(cert.toString());
        }

Method getEncoded() of Certificate returns byte[] which allows you save it in a file.

Reference

a blog from internet

java.security.cert.Certificate api

Using proxy in http connection