Java Api that wraps the Trade.it Json API Detailed Trade It API documentation can be found here: https://www.trade.it/api.
The JCenter repo can be found here: https://bintray.com/tradeit/maven/tradeit-java-api
For examples usage, see the tests included with the Java Api or look into the AndroidSDK implementation and tests: https://github.com/tradingticket/AndroidSDK.