I am trying to send a transaction to an address: 0xDD210......... using the EthSendTransaction.sendTransaction() method from the org.web3j.protocol.core.methods.response.EthSendTransaction library.

The transaction contains data but doesn't have any value (I don't have to send funds). I am using the private network(localhost: 8545)

The syntax is:

EthSendTransaction transactionResponse = transactionManager.sendTransaction(220000000,
            43000, "0xDD210......", hashedData.toString(), BigInteger.valueOf(0));

String transactionHash = transactionResponse.getTransactionHash();   

The value of transactionHash is null.

if (transactionResponse.hasError()) {
        logger.info("in error block");
        throw new RuntimeException(
                "Error processing transaction request: " + 

On runtime, the code gives

"Error processing transaction request: Invalid params: invalid hex."

Does anyone know the solution to this?

2 Answers 2


Did you try something like this:

Transaction transaction = Transaction.createFunctionCallTransaction("FROM_ADDRESS",  nonce, gasprice, gaslimit, "TO_ADDRESS", encodedData);

EthSendTransaction transactionResponse = web3j.ethSendTransaction(transaction).sendAsync().get();
transactionHash = transactionResponse.getTransactionHash();

(can you share more of your code, like the method in your smartcontract, how you init the transactionManager and how you get the hashedData?)

I usually do this

Credentials credentials = WalletUtils.loadCredentials("Your PASSWORD", "Your Wallet-File-Location");

// Get Nonce
EthGetTransactionCount ethGetTransactionCount = web3j
                .ethGetTransactionCount(credentials.getAddress(), DefaultBlockParameterName.LATEST).send();
BigInteger nonce = ethGetTransactionCount.getTransactionCount();

RawTransaction rawTransaction = RawTransaction
            .createTransaction(nonce, "Your GASPRICE", "Your GASLIMIT", "Your Contract-Address", "Your encodedFunction");

// Sign the Transaction
byte[] signedMessage = TransactionEncoder.signMessage(rawTransaction, credentials);
String hexValue = Numeric.toHexString(signedMessage);

EthSendTransaction transactionResponse = web3j .ethSendRawTransaction(hexValue ).sendAsync().get();

Of course with RawTransaction you should sign the transaction and set nonce (I think that a transactionmanager does it for you)

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