import com.veriplace.client.Client;
import com.veriplace.client.VeriplaceException;

import javax.servlet.http.HttpServletResponse;

final String callback = "http://example.com/veriplace";
try {
    final String redirectUrl = client.getUserDiscoveryAPI().getRedirectURL(callback,null);
    response.sendRedirect(redirectUrl);
} catch (VeriplaceException e) {
}