Can I repair this corroded shutoff valve on my own?

I just noticed that this valve is corroded and slowly leaking (arrows point to the leaks):

I started looking online for information and found this page, which discusses different types of valve, but I can't really tell whether this is a compression shutoff valve (install with wrenches) or a copper sweat shutoff valve (solder into place). Which is it, and is this a repair that I can make myself, or should I bring in a professional?