Bitcoind Json Rpc Client for Java

This is a Java library to call the Json Rpc API of the reference implementation Bitcoind. The goal is to support all methods listed in the ./bitcoind help-command. The implementation started from version 8.3 of Bitcoind and will not support previous versions. For further details about the implemented API visit the bitcoin.org wiki.

Build

Having OpenJDK 7 and Maven 3 installed, execute:

  mvn clean install

Usage

Maven will need to know where to search for this artifact. Add this to your pom.xml:

  <repository>
    <id>github</id>
    <name>GitHub BitcoindClient4j Repository</name>
    <url>https://raw.github.com/johannbarbie/BitcoindClient4j/mvn-repo</url>
  </repository>

Then add the dependency itself:

  <dependency>
    <groupId>com.37coins</groupId>
    <artifactId>BitcoindClient4j</artifactId>
    <version>0.1.0</version>
  </dependency>

Having dependencies resolved, you can code away. First initialize the Factory with network parameters:

  BitcoindClientFactory clientFactory = 
      new BitcoindClientFactory(
          new URL("http://localhost:8332/"), 
          "user", 
          "password");

Then get a client instance:

  BitcoindInterface client = clientFactory.getClient();

Now you can make calls to your node:

  Info info = client.getinfo();

If you had the API start your bitcoind, you might be interested in stopping it again:

  client.stop();

Blockchain Events

The library also captures notifications from Bitcoind using the startup configuration. Launch your deamon with those parameters:

  ./bitcoind  -blocknotify="echo '%s' | nc 127.0.0.1 4001" 
              -walletnotify="echo '%s' | nc 127.0.0.1 4002" 
              -alertnotify="echo '%s' | nc 127.0.0.1 4003" 
              -daemon

Or, if you have your bitcoind locally, have the API start up the daemon. Call the factory with a path instead of network parameters:

  BitcoindClientFactory clientFactory = 
      new BitcoindClientFactory(
          "/home/user/.bitcoin/",
          Arrays.asList("./bitcoind"));

You can register observers to capture events about blocks, addresses in you wallet, and alerts:

  new BlockListener(client).addObserver(new Observer() {
    @Override
    public void update(Observable o, Object arg) {
      Block block = (Block)arg;
    }
  });

Make sure to close sockets later:

  blockListener.stop();

Donations

Bitcoin donations can be sent to:

  152jsQJyQwxRywuHVVGLFEHkZqJ4QzuFS3

Thanks!

License

GPL3, see LICENSE.txt