Java open source histogram

I need a histogram class for a project. I am not interested in the graphical representation, only in the "book keeping". Ideally, it should be able to also give me cutoffs( for example, 80% cutoff should output lower and upper limit that contain 80% of the data, and the cutoffs to be approximately symmetric around the center). Any idea what 开发者_如何学Ccan I use and where can I find it?