Hello everyone! I have a question regarding web3j. Do you know how can I know public and private key from existing ethereum wallet (I created it for testnet)? Web3j requires to set public and private key to perform transaction that changes blockchain state. Thank you.
@danieldietrich if the gas used by the transaction deployment = gas limit, this would imply one of two things:
- The gas limit isn’t high enough for the smart contract
- There’s an error in the smart contract itself causing the gas to be used up
Given you said that it worked using the JavaScript deployment, please can you confirm the gas limit that was used when it was deployed successfully?
@vladislavdmitriev you can use WalletUtils to load the Ethereum wallet file https://docs.web3j.io/transactions.html#creating-and-working-with-wallet-files
@conor10
We deployed the same contract using web3.js to the same (private) geth node.
g$ geth version
Geth
Version: 1.5.9-stable
Git Commit: a07539fb88db7231d18db918ed7a6a4e32f97450
Protocol Versions: [63 62]
Network Id: 1
Go Version: go1.7.3
OS: linux
GOPATH=
GOROOT=/usr/lib/go-1.7This is the transaction receipt:
{
"blockHash": "0xf2d36a31d5fa687615b5df6cde1a4b56c692d07b8ce302d6055cf353add07532",
"blockNumber": 50017,
"contractAddress": "0x0509792e0ed7e8e23f3d34b458a266a85512186f",
"cumulativeGasUsed": 1048006,
"from": "0xd16336a9f47074ca5fb539b972f7e4451f25a997",
"gasUsed": 1048006,
"logs": [],
"logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
"root": "0x0dd342b1f9c7b3e7cacc97de56068545fd7a9c4e7156269117cd654c7661ff01",
"to": null,
"transactionHash": "0xd486ecbf1139a841c4043c2a616af382afe00976034cd6210a1f7d62edcdb32b",
"transactionIndex": 0
}| library | gas used |
|---|---|
| web3.js | 1048006 |
| web3j | 4300000 |
However, there is still one difference between our two scenarios, Java and Javascript:
- For Javascript we compile the contracts using the node module
solc.jsversion0.4.9 - For Java we compile the contracts using the binary for Mac OS:
/usr/local/bin/solcversion0.4.9+commit.364da425.Darwin.appleclang
You can try swapping out the OS X Solidity bytecode (from the ABI file) with the compiled JS Solidity bytecode in the smart contract wrapper file - that will help identify if the issue lies in Solidity versions or web3j
yep - I also prepared that suggestion this moment :) ------->
There is no constructor present, only one private contract variable:
mapping(address => OtherContract[]) private otherContracts;I compared the ABI and BIN data generated by solc.js and the binary solc distribution (with and without the --optimize flag). The ABIs are the same, the BINs differ.
I will now generate the wrappers based on the BINs created by solc.js and look what happens when deploying them with Java...
Need to move to office - will come back....
@conor10
When deploying the contract using the abi/bin created with solc.js I get the same result:
- The server logs say that the contract is deployed and I receive the address
- The transaction receipt shows a way too high gas-used: 4300000
My Javascript code is test code. I do not sign the transaction and I unlocked the account on the server side.
function deploy(contract, user) {
web3.eth.contract(contract.abi).new({
data: contract.binary,
from: user,
gas: TX_COST_LIMIT // = "3141592"
}, (error, contractInstance) => /* handler code */)
}For the Java code I copied the wallet from the server side to the client side because the contract wrappers need credentials.
Next step: Now I will create a raw transaction with Java
I created a Transaction with Java to deploy the contract (using the Javascript Binary):
String from = "0x<my-user>";
EthGetTransactionCount ethGetTransactionCount = web3j.ethGetTransactionCount(
from, DefaultBlockParameterName.LATEST).send();
BigInteger nonce = ethGetTransactionCount.getTransactionCount();
String BINARY = "0x<my-binary>";
Transaction transaction = Transaction.createContractTransaction(
from,
nonce,
gasPrice,
gasLimit,
gasValue,
BINARY);
EthSendTransaction transactionResponse =
web3j.ethSendTransaction(transaction).send();
String transactionHash = transactionResponse.getTransactionHash();
`Same result. Transaction receipt:
{
"blockHash": "0x1156e969c888585cc11269c5d5d3cbef79bb719afddaa669a3ca31cb7b9ec5b1",
"blockNumber": 51089,
"contractAddress": "0x5df2c361206dc35ae03fc8049bbe1340e28a7948",
"cumulativeGasUsed": 4300000,
"from": "0xd16336a9f47074ca5fb539b972f7e4451f25a997",
"gasUsed": 4300000,
"logs": [],
"logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
"root": "0xfcbd82026383e04e2bd5a062b8ff03c42b637ae37a01d2a0a6ea096ba37087ef",
"to": null,
"transactionHash": "0x86d96471ceb7eb7059e04376a1bdd8ddda86addf399a9b0796a3d045309c8912",
"transactionIndex": 0
}I could now go s step backwards and create a simpler contract.
But the question remains: Why behave web3j and web3js different.
I could also change the contract and variable names and publish them (in a private gist?) for further investigation.
/cc @conor10
@danieldietrich please do create a private Gist. You can work around this issue by using web3j's ClientTransactionManager instead of RawTransactionManager, but I'd like to get the the bottom of the issue. There was an RLP encoding fix (used by raw transactions) that went out with the 2.0 release which I presume you're already using
then poll periodically for responses
Web3j web3j = Web3jFactory.build(new HttpService(url));
List<Type> inputParameters = new ArrayList<>();
List<TypeReference<?>> outputParameters = new ArrayList<>();
Function function = new Function("getManufacturer",
inputParameters,
outputParameters);
String functionEncoder = FunctionEncoder.encode(function);
EthCall response = web3j.ethCall(
Transaction.createEthCallTransaction(contractAddress, functionEncoder),
DefaultBlockParameterName.LATEST
).sendAsync().get();
List<Type> someType = FunctionReturnDecoder.decode(response.getValue(), function.getOutputParameters());
Type resault = someType.get(0);
String a = resault.toString();
Log.d("MainActitity", a + "111");i copy this function Querying the state of a smart contract
@wbinSong it's easier to use the web3j smart contract wrappers to work with smart contracts, see https://docs.web3j.io/smart_contracts.html#solidity-smart-contract-wrappers
But this nonce may have already been used. I realize this is impossible to solve at library level, because nonce may be changed from another place, which is out of control.
@dstarcev I created the following transaction manager for supporting higher transaction throughput (https://github.com/web3j/web3j/blob/master/src/main/java/org/web3j/tx/FastRawTransactionManager.java) and @ferOnti has played around with his own too. What's the crashing that you're seeing?
this is because I send transactions that are the same. Only the nonce is different
ah fine, so it's an error with sending multiple transactions per block. I'd recommend either you take a look at the FastRawTransactionManager, or if you want to use the normal transaction manager, it would be worthwhile contributing to the following discussion web3j/web3j#54 - currently its not been clarified if this could provide a solution to sending multiple transactions
a simple DTO instead of
List<Type>
POJO I mean
or is it not present in abi?
Ok, I see the name of a struct is not present, but we still can return something more typed
the web3j block Observable takes care of that for you, but is polling behind the scenes. The only other way to receive notification without polling is via a WebSocket connection to Geth (https://github.com/ethereum/go-ethereum/wiki/RPC-PUB-SUB), support for this has not been added to web3j yet
@conor10 i've managed to solve the mentioned issues, thanks for your help! Now, i've another problem..i'm using oraclize, and after invoking oraclize method, oraclize will invoke my contracl callback method which fires an event with the return value, but this process is asynchronous. Using web3j, how can i "wait" for this event? I've used observables and filters, but nothing works.
pragma solidity ^0.4.4;
import "./usingOraclize.sol";
contract QuerySensor is usingOraclize {
event newOraclizeQuery(string indexed description);
event newQuerySensor(string indexed price);
event res(string indexed desc);
event querySensorStarted(string indexed descp);
function QuerySensor() {
querySensorStarted("Query Sensor INITIATED");
}
function __callback(bytes32 myid, string result) {
if (msg.sender != oraclize_cbAddress()) throw;
newQuerySensor(result);
}
function update() payable {
newOraclizeQuery("Oraclize query was sent, standing by for the answer..");
oraclize_query("URL", "xml(https://www.fueleconomy.gov/ws/rest/fuelprices).fuelPrices.diesel");
}
function hw() {
res("hello world");
}
}