Java appears as a dark, rich, and cool shadow in the pan, but on my skin, it is a medium-toned ashy metallic brown that is very lightly pigmented. I don't care for the texture, which is gritty; I own several of BB metallics and they all have the same texture, so they don't get much use.
I won't use Java in my crease, because I prefer to contour with a matte shadow, but it adds a pretty, subtle gleam to lids if you're willing to work at layering to get the color to show up. Not overly shimmery or sparkly at all -- it's just not worth the effort. I consider it a specialty color, not a staple.
Java is a satiny dark coffee with milk brown. Its neutral, neither cool or warm toned. This is not deep or pigmented enough for me to line with but enough to do some contouring and shading. Overall this is a good staple to have in your kit.