I'm looking for a Java payment gateway library similar to the Rails active_merchant or the libraries available on many other platforms. I've been surprised that I've been unable to find one. I'd like something that supports the major gateways and providers, like Paypal, Google, Amazon, and some direct merchant account providers like Authorize.net.
Does such a thing exist in the open source world?
Stripe has a Java library to accept credit cards without needing a merchant account: https://github.com/stripe/stripe-java
Check out the documentation and FAQ, and feel free to drop by our chatroom if you have more questions.
I found nice paypal library at sourceforge: http://sourceforge.net/projects/paypal-nvp/
来源：https://stackoverflow.com/questions/2242653/java-payment-gateway-library