microsoft-azure-storage/src/com/microsoft/azure/storage/core/Utility.java
private static boolean isHostDnsName(URI uri) {
        String host = uri.getHost();
        for (int i = 0; i < host.length(); i++) {
            char hostChar = host.charAt(i);
            if (!Character.isDigit(hostChar) && !(hostChar == '.')) {
                return true;
            }
        }
        return false;
    }
private static boolean isHostDnsName(URI uri) {
        String host = uri.getHost();
        for (int i = 0; i < host.length(); i++) {
            char hostChar = host.charAt(i);
            if (!Character.isDigit(hostChar) && !(hostChar == '.')) {
                return true;
            }
        }
        return false;
    }
Returns a boolean indicating whether the host of the specified URI is DNS.

@param uri
The URI whose host to evaluate.
@return <code>true</code> if the host is DNS; otherwise, <code>false</code>.