You can sign up for a Realex Payments account at https://developer.realexpayments.com.
Java 1.6 and later.
Add this dependency to your project's POM:
<dependency>
<groupId>com.realexpayments.hpp.sdk</groupId>
<artifactId>rxp-hpp-java</artifactId>
<version>1.3.3</version>
</dependency>
Add this dependency to your project's build file:
compile "com.realexpayments.hpp.sdk:rxp-hpp-java:1.3.3"
HppRequest hppRequest = new HppRequest()
.addAmount(100)
.addCurrency("EUR")
.addMerchantId("merchantId");
RealexHpp realexHpp = new RealexHpp("mySecret");
String requestJson = realexHpp.requestToJson(hppRequest);
RealexHpp realexHpp = new RealexHpp("mySecret");
HppResponse hppResponse = realexHpp.responseFromJson(responseJson);
See the LICENSE file.