We don't really know the context of this code. Ulf's answer assumes it's inside a method (or inside a constructor or initialization block). In that case the braces don't do much other than group things for human readability, and restrict the scope of local variables. If you need to do this sort of thing, it's usually better to just create new methods for each of the blocks.
However, if the code shown is nested inside a class, but not inside a method (or constructor or initializer block), then the braces represent an instance initializer block. You can learn more about these in the
Java Tutorial.