This is not exactly an answer to the question... but if a broker has C/C++ API you can always create a Java wrapper using JNI.
Open source examples of what? JNI? It's part of the language. I thought you decided to go with FIX in another thread which would make language choice irrelevant.
Yep... Considered ... fix but some expirienced posters made point that it is not designed for tradeing.... So I decised to continue search... And better explore fast brokers... And their Own APIs.... Keep seaeching !
It's not exactly boroker APIs but the best place to start is Sun Web-site. Programmer's Guide Collection of JNI links for Java 6
I think PATSystems J-Trader is Java based. I have not used it but remember seeing it as one of the trading platforms offered by Global Futures.
big difference between lime & sterling. Sterling is a single-threadded app so Java will be a waste of time IMHO. Pretty sure Lime has an example of their API, or at least documentation on their website and its public.
Are you sure... Last time I spoke with Line They were paranoid about their API... They wanted a meeting (phone) before they decide IF they can send the documenation....