Hi Anders, you can find a description in this book: Internet Applications in LabVIEW by Jeffrey Travis, it's a must! There's a full chapter for using Java in LV. You can Get the book from NI, I bought it on Amazon.com
The DataSocket JavaBean API comes as javadoc HTML files with the DataSocket JavaBean purchase. This is an online purchase that can be started from here.
Randy Hoskin Applications Engineer National Instruments http://www.ni.com/ask