Ether transfer from one account to another account using Web3j and Java

 
        
			org.web3j
			core
			2.2.2
		
 

 
Web3j web3j = Web3j.build(new HttpService("Ethereum server ip with port"));
 

 
Credentials credentials = WalletUtils.loadCredentials(
						"Password of sender account",
						"Ethereum server blockchain keystore path" + "/" + "Sender account wallet file name");

 

 

 public Map transferEtherAccountToAccount(BigDecimal balance) throws IOException {
	Map result = new HashMap<>();
		try {
			Web3j web3j = Web3j.build(new HttpService(envConfiguration.getTestnetServerIp()));
			LOGGER.info("--------------Enter into transferEtherAccountToAccount function");

                        // Find the wallet from database which is used as sender address
			UserWallet wallet = userWalletRepository.findByAddress(address);
			BigInteger amount = web3j.ethGetBalance(wallet.getAddress(), DefaultBlockParameterName.fromString("latest")).send()
					.getBalance();


			LOGGER.info("Creating  Parity...");

			LOGGER.info("Getting wallet ..." + wallet.getAddress() + "  and balance is "
					+ web3j.ethGetBalance(wallet.getAddress(), DefaultBlockParameterName.fromString("latest")).send()
							.getBalance());
                        // Minimum gas is 21000 used for transaction
			BigInteger gas = BigInteger.valueOf(21000);
			LOGGER.info("gas:::" + gas);

			BigInteger xth = new BigInteger("1000000000000000000");
			LOGGER.info(":::Transferred amount is::::" + amount);
                       
                        // Pick gas price from geth console
			BigInteger gasprice = web3j.ethGasPrice().send().getGasPrice();

			LOGGER.info("gasprice:::" + gasprice);

			BigInteger gaslimit = BigInteger.valueOf(4800000);
			LOGGER.info("gaslimit:::" + gaslimit);

                        // Calculate transaction fees for transaction 
			BigInteger txnFee = gas.multiply(gasprice);

                        // Validate balance to perform transaction fees
			int compareResult = amount.compareTo(gas.multiply(gasprice));
			LOGGER.info("Compare result:: " + compareResult);

			LOGGER.info(":::Transferred amount is :::" + amount);
			if ((compareResult != 0 && compareResult != -1)
					&& wallet.getAddress() != web3.ethAccounts().send().getAccounts().get(0)) {

				Credentials credentials = WalletUtils.loadCredentials("Password of sender account", "sender account path with file name" );
				LOGGER.info("credentials:::from address:::" + credentials.getAddress());

			
				LOGGER.info("--------------Wallet keystore location is "
						+ envConfiguration.getTestnetkeyStorePath().trim() + "/" + wallet.getWalletFileName());
				EthGetTransactionCount ethGetTransactionCount = parity
						.ethGetTransactionCount(parity.ethAccounts().send().getAccounts().get(0),
								DefaultBlockParameterName.LATEST)
						.sendAsync().get();
				LOGGER.info("--------------ethGetTransactionCount" + ethGetTransactionCount.getTransactionCount());
				
				// get the next available nonce
				BigInteger nonce = ethGetTransactionCount.getTransactionCount();
				LOGGER.info("----------nonce" + nonce);

				BigDecimal gasInDecimal = new BigDecimal(gas);
				BigDecimal gaspriceInDecimal = new BigDecimal(gasprice);

				balance = balance.subtract((gasInDecimal.multiply(gaspriceInDecimal)).divide(new BigDecimal(xth)));
				LOGGER.info("::::gasInDecimal:>>>>>>>>>>>>>>>>>>>>>>>>>>>>:" + gasInDecimal
						+ "::gaspriceInDecimal:::::::" + gaspriceInDecimal);
				LOGGER.info(":::Transferred amount is::::>>>>>>>>>>>>>>>>>>>>>" + balance);
	

				LOGGER.info("Enter into account Unlocked ..>>>>>>>>>>>>>>>>>>>>>>.");
				
				TransactionReceipt transactionReceipt = Transfer.sendFunds(parity, credentials, "Receiver Eth address",
						balance, Unit.ETHER);
				LOGGER.info("trn recpt " + transactionReceipt.getTransactionHash() + " new balance is "
						+ parity.ethGetBalance(wallet.getAddress(), DefaultBlockParameterName.fromString("latest"))
								.send().getBalance());

			
				result.put("responseMessage", "success");
				return result;

			} else {
				result.put("message", "error");
				result.put("responseMessage", "failure");
				return result;
			}

		} catch (Exception e) {
			result.put("trnInfo", null);
			result.put("message", e.getMessage());
			result.put("responseMessage", "failure");
			return result;
		}
	}