Introduction

This project is a java library that is intended to provide a wrapper around JSON-RPC provided by Bitcoin/Litecoin.

It has been tested on Litecoin. I wrote it for one of my projects.

The main dependencies of this project are

*   **Htmlunit**	
*   **Google Gson**

Since this was intended for use in a proprietary project, I've tried to write as much javadoc as possible as to what the method does.

JSON-RPC calls for Litecoin & Bitcoin are same as you can see below, so this work shall work with both. If it doesn't please let me know by filing an issue.

Litecoin RPC API Calls

Bitcoin RPC API Calls

This project assumes that the one who uses it has a preliminary knowledge about Bitcoin/Litecoin and how to start the RPC server.

Running Litecoin

Running Bitcoin

Sample Usage

public static void main(String[] args) throws Exception {
    final String rpcUser = "rpcuser";
    final String rpcPassword = "password";
    final String rpcHost = "localhost";
    final String rpcPort = "9332";
    CryptoCurrencyRPC cryptoCurrencyRPC = new CryptoCurrencyRPC(rpcUser, rpcPassword, rpcHost, rpcPort);

    cryptoCurrencyRPC.setAccount("account","LCYEnDaddressENBYCEYD235NSD");
    
    //Similarly, all the API methods can be called.
}

Blockchain Events

(part of the code was taken from https://github.com/johannbarbie/BitcoindClient4J)

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

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

You can register observers to capture events of wallets, and alerts:

    WalletListener walletListener = new WalletListener(cryptoCurrencyRPC, 4002);
    walletListener.addObserver(new Observer() {
        @Override
        public void update(Observable o, Object arg) {
            Transaction tx = (Transaction) arg;
            BigDecimal amount = tx.getDetails().get(0).getAmount(); //amount of transaction
            String txId = tx.getTxid(); //id of transaction
            Transaction txDetails = tx.getDetails().get(0); //transaction details

            if (tx.getDetails().size() == 2) {
                //both side of translation inside your bitcoind node
                String sendToAddress = txDetails.getAddress();
                String receiveAddress = tx.getDetails().get(1).getAddress();
                BigDecimal fee = tx.getFee();
            } else {
                //one side of translation outside of your bitcoind node
                switch (txDetails.getCategory()) {
                    case RECEIVE: //your account on bitcoind receive bitcoin
                        String receiveAddress = txDetails.getAddress();
                        break;
                    case SEND:  //your account on bitcoind send bitcoin
                        //the address to which the coins was sent
                        String sendToAddress = txDetails.getAddress();
                        //account in your bitcoind from which the coins was sent
                        String sendFromAccountName = txDetails.getAccount();
                        BigDecimal fee = txDetails.getFee();
                        break;
                    default:
                        //Strange transaction: MOVE or CONFLICTED
            }
        }
    });

Make sure to close sockets later:

  walletListener.stop();

Logs and exception handling

All log files are written via log4j DailyRollingFileAppender and saved in /var/log/bitcoin-rpc/ folder.

Library can generate listed below types of Runtime exception:

• AuthenticationException
• CallApiCryptoCurrencyRpcException
• CryptoCurrencyRpcException (base class)
• InsufficientFundsException
• RpcInvalidResponseException

Written with StackEdit.