SSL certificate download from the https server so you dont have to manually download it through browser or keytool.

DownloadSSLCertificate

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

/**
 * 
 * @author chouhan_r
 *
 */
public class DownloadSSL
{

	private static final String SEPERATOR = System.getProperty("file.separator");

	public static void downloadSSLCertificate(){
		String httpsURL = "https://localhost:8443";
		if(httpsURL != null && httpsURL.contains("https")){
			FileOutputStream writer = null;
			try {
				URL myurl = new URL(httpsURL);
				SSLContext ssl = SSLContext.getInstance("TLSv1");
				ssl.init(null, new TrustManager[] { new SimpleX509TrustManager() },
						null);
				SSLSocketFactory factory = ssl.getSocketFactory();
				HttpsURLConnection con = (HttpsURLConnection) myurl.openConnection();
				con.setSSLSocketFactory(factory);
				InputStream ins = con.getInputStream();
				String filePath = "sslcertificate.cer";
				File file = new File(filePath);
				writer = new FileOutputStream(file);
				for (Certificate cert : con.getServerCertificates()) {
					writer.write(cert.getEncoded());

				}
				
			} catch (Exception e) {
				e.printStackTrace();
			}finally{
				if(writer!=null){
					try {
						writer.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}
			
			System.out.println("certificate downloaded");
		}
		
	}

}

class SimpleX509TrustManager implements X509TrustManager {
    public void checkClientTrusted(
            X509Certificate[] cert, String s)
            throws CertificateException {
    }

    public void checkServerTrusted(
            X509Certificate[] cert, String s)
            throws CertificateException {
      }

    @Override
    public X509Certificate[] getAcceptedIssuers() {
        // TODO Auto-generated method stub
        return null;
    }

}

Download SSL certificate from the https server pragmatically. No need to download it manually like from web browser or keytool.