I'm trying to send raw transaction with Web3j, to call a smart contract function.

I try to set very high values for gas to avoid problems with it.

But I always get a null tx hash. What is wrong in my code ?

    // get nonce
        EthGetTransactionCount ethGetTransactionCount = web3j.ethGetTransactionCount(
                ethereumAddress, DefaultBlockParameterName.LATEST).sendAsync().get();
        BigInteger nonce = ethGetTransactionCount.getTransactionCount();
        log.debug("nonce: "+nonce.toString());

        // build function call
        Function function = new Function(
                Arrays.asList(new Address(subjectAddress), new Utf8String(claimId), new Utf8String(claimValue), new DynamicBytes("".getBytes())),

        // encode function call to tx data
        String encodedFunction = FunctionEncoder.encode(function);
        log.debug("encodedFunction: "+encodedFunction);

        RawTransaction rawTx = RawTransaction.createTransaction(
                ,DefaultGasProvider.GAS_PRICE.multiply(new BigInteger("1000000"))
                ,DefaultGasProvider.GAS_LIMIT.multiply(new BigInteger("1000000"))

        byte[] signedMessage = TransactionEncoder.signMessage(rawTx, Credentials.create(privateKey));
        String hexValue = Numeric.toHexString(signedMessage);

        EthSendTransaction ethSendTransaction = web3j.ethSendRawTransaction(hexValue).send();

        String transactionHash = ethSendTransaction.getTransactionHash();
        log.info("Tx hash: "+transactionHash);

I've tried this with Ganache and Infura. Both of them log an eth_sendRawTransaction. But I got no error, no message.


  • 1
    How much is gasPrice and gasLimit? Do you have enough ethers to pay? You need at least gasPrice * gasLimit. If gasLimit is higher than the block gas limit the transaction will fail, block gas limit is 15M in mainnet, 8M in ropsten, 8M in goerli, 10M in rinkeby.
    – Ismael
    Commented May 25, 2021 at 16:08
  • In Web3j, default gas limit=9M and gas price = 41M. To be sure it was enough, I multiplied it. As I'm on Ropsten, it's not a matter of cost, at least to test the raw tx feature. I didn't know there was top limits too.
    – avl
    Commented May 27, 2021 at 6:31
  • Usually you want gasLimit to be closer to how much the transaction will use. In solidity versions previous to 0.8 some error would consume all available gas.
    – Ismael
    Commented May 27, 2021 at 18:39

1 Answer 1


Self answering my question for interested people:

I found in web3j doc ethSendTransaction.getError() :

EthSendTransaction ethSendTransaction = web3j.ethSendRawTransaction(hexValue).send();

if(ethSendTransaction.getError() != null)

And I could get information that my gas limit was too high.

(slapping myself) Thought of the day : "If it's not broken, don't fix it".

But usefull information is that in web3j, event the default gas limit DefaultGasProvider.GAS_LIMIT is too high for testnets.

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