Paypal Button and Instant Payment Notification (IPN) Integration with Java - http://codeoftheday.blogspot.com/2013/07/paypal-button-and-instant-payment_6.html

Paypal Button HTML Code.html

<!--
  Paypal Button and Instant Payment Notification (IPN) Integration with Java
  http://codeoftheday.blogspot.com/2013/07/paypal-button-and-instant-payment_6.html
-->

<form action="https://www.paypal.com/cgi-bin/webscr" method="post" target="_top">
<input type="hidden" name="cmd" value="_s-xclick">
<input type="hidden" name="hosted_button_id" value="XXXXXXXXXXXXX">
<input type="hidden" name="return" value="http://www.yourdomain.com/orderComplete.do">
<input name="notify_url" value="http://www.yourdomain.com/your_ipn_listener.do" type="hidden">
<input type="image" src="https://www.paypalobjects.com/en_US/GB/i/btn/btn_buynowCC_LG.gif" border="0" name="submit" alt="PayPal ? The safer, easier way to pay online.">
<img alt="" border="0" src="https://www.paypalobjects.com/en_GB/i/scr/pixel.gif" width="1" height="1">
</form>