To get started, ensure you have the latest JDK installed, and download Maven from:

http://maven.apache.org/

Then run "mvn clean package" to compile the software. You can also run "mvn site:site" to generate a website with useful information like JavaDocs. The outputs are under the target/ directory.

Now ensure you're running a BitCoin node locally and run the example app:

cd out java com.google.bitcoin.examples.PingService

It will download the block chain and eventually print a BitCoin address. If you send coins to it, you should get them back a few minutes later when a block is solved.

Note that if you connect to a node that is itself downloading the block chain, you will see very slow progress (1 block per second or less). Find a node that isn't heavily loaded to connect to.

If you get a SocketDisconnectedException, the node you've connected to has its max send buffer set to low (unfortunately the default is too low). Connect to a node that has a bigger send buffer, settable by passing -maxsendbuffer=25600 to the Bitcoin C++ software.