Disclaimer: I work for Snipcart
The advantage of Snipcart over other solutions is that it's independent of your other stack choices. You can select your backend tech based on what you're the most comfortable with.
If Java, Bootstrap and jQuery are requirements for the project, Snipcart won't get in the way of those. That's one of the big selling points, it can provide a lot of features for platforms that don't have a feature-full ecommerce framework.
I wouldn't know which Java-based ecommerce platform to recommend and compare to. There seems to be a few but none with big market shares or recognized name.
If Java isn't a strong requirement of the project, I'd look into PHP and Ruby/Rails solutions as they have more mature ecommerce solutions.
