Questions tagged [web3j]
Lightweight Java and Android library for integration with Ethereum clients
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13 views
Quorum deploy with Web3j timeout
SCENARIO:
I have the following code:
final String hostUrl = this.deployerProperties.getProperty("quorum.host.url");
final String hostPort = this.deployerProperties.getProperty("quorum.host.port");
...
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0answers
6 views
Could someone explain to me the use of the FastRawTransactionManager class?
int pollingInterval = 3000;
FastRawTransactionManager fastRawTxMgr = new FastRawTransactionManager(web3j, credentials, new PollingTransactionReceiptProcessor(web3j, pollingInterval, 40));
From what I ...
0
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0answers
18 views
Transaction receipt was not generated after 600 seconds for transaction:
I am sending a transaction through this code:
txhash = careercertificate
.createCertificate(id, fecha, nombre, rutalumno, instituto, rutinstituto, titulo, totalhash, ...
0
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1answer
34 views
Sending private key to server side
I am trying to build new Dapp application for our startup by using web3j , I am facing an issue with signing the transaction from server side , because i need to know the private key for the client (...
1
vote
1answer
50 views
Empty value (0x) returned from contract web3j
I'm trying to deploy a very simple contract on Windows 10, using Web3j 4.2.0. I've created an account using Mist. I've set up one local ethereum node (using geth) on my machine and I'm able to deploy ...
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0answers
12 views
Load smart contracts in Java application without having the java wrapper class for Web3j (only the address of the contract)
I use web3j to interact with my local Ethereum node (created with geth), and I was wondering how should I handle smart contracts created at runtime.
I know that in order to deploy a smart contract ...
0
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0answers
14 views
Send ether from one wallet to another
I have two metamask accounts and what I want to do is send ether between those accounts. For the interaction between those accounts, use infura, I give the address of both accounts but in the end the ...
0
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1answer
39 views
invalid opcode “0x1c” during smart contract method execution
I have written a smart contract to test event from java project using web3j
I have prepared the web3j wrapper java class using solc compiler version
"0.5.7+commit.6da8b019.Linux.g++"
I am using a ...
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0answers
23 views
Invalid OPCode on passing address parameter through Java wrapper on smart contract using Ganache
I have been facing this issue for some time and I realized there must be a problem with Ganache or maybe someone has any idea why it doesn't work.
I have created a very simple contract as below, it ...
1
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2answers
28 views
Offline transaction signing with web3j?
I'd like to generate and sign a transaction offline and then send that transaction with a different account. I've found a few web3js sources and I've read the web3 documentation, but I haven't found ...
0
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1answer
59 views
What's problem about “gas required exceeds allowance or always failing transaction”
I translate smart contract into Java with solc and web3j, but I meet the probelm "gas required exceeds allowance or always failing transaction".
This is my smart contract.
It is work when I use ...
1
vote
1answer
27 views
Is it worthwhile to store my supply chain product data on the blockchain using a smart contract? [closed]
I'm currently developing an android app that uses the Web3j framework (Java) to interact with my private Ethereum blockchain (running on Ganache). The app is a supply chain tool that will let users ...
0
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2answers
40 views
Unable to make a transaction with Data using Java api ethSendRawTransaction
I am trying to make a transaction between two different accounts using Java. It works perfectly fine as long as I am not using "Data" parameter.
My intent is not to call a smart contract but to make ...
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0answers
44 views
web3j.ethCall returns null when retrieven contract variable
Environment:
Geth node Geth/v1.9.0-unstable/windows-amd64/go1.12
Commands used to start the node to mine:
geth --datadir "." --networkid 101 -verbosity 6 --port 30301 --rpcport 8101 --nodiscover
-...
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0answers
15 views
ERC-20 TransferFrom function exceeds GasLimit calling from other conract
I have the following error. Imagine that I have contract A, B(ERC20 implementation contract), C, D and E. They are inherit in that order. Testing the functionallity works fine in remix. But when I try ...
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0answers
9 views
Catching FilterException web3j
I'm using web3j to subscribe for transactions:
Flowable<Transaction> observable =
web3.replayPastAndFutureTransactionsFlowable(startBlockParameter);
Scheduler ...
1
vote
2answers
61 views
Get function returned 2 values in Web3j
I wrapped a smart-contract generated in remix into a Java Project. Im trying to get the two values that return me this function.
function getValues(address _a) external returns(bool, uint32) {
...
0
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1answer
102 views
org.web3j.tx.exceptions.ContractCallException: Empty value (0x) returned from contract
Problem:
org.web3j.tx.exceptions.ContractCallException: Empty value (0x) returned from contract
The code is as follows....
My java:
String owner = managedWalletLookup.getOwner(contractAddress).send(...
2
votes
2answers
47 views
Too low nonce error with web3j and rinkeby
All of sudden my application on testnet has stopped working due to low nonce error. No change in source code. My app connects to the network via infura. Any ideas what could be wrong here.
java.lang....
0
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1answer
40 views
how to find if a Tx hash is in pending state in ethereum mainnet after web3j fastTxMgr timeout
I am using QueuingTransactionReceiptProcessor() with callback accept(). DEFAULT_POLLING_ATTEMPTS_PER_TX_HASH is 10 and POLLING_FREQUENCY is 15000. That gives nearly 3 min wait for network to ...
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0answers
46 views
Build web3j to connect to blockchain [duplicate]
Can't connect to the Ethereum blockchain with web3j 4 for Android Kotlin. Worked in the previous version of web3j.
fun web3(): Web3j = Web3jFactory.build(HttpService("http://192.168.38.148:7545"))
...
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0answers
39 views
Subscribe to changes in contract balance (Web3j)
Using web3j I would like to subscribe to changes in a contract balance i.e deposits and withdraws.
I would like to base this subscription over transactions (and not events) since the contract does ...
0
votes
1answer
56 views
Quorum node address
In the Node class of the Quorum Web3j. The String address what is?
package org.web3j.quorum;
import java.util.List;
/**
* Quorum node configuration class.
*/
public class Node {
private final ...
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0answers
96 views
Error: replacement transaction underpriced web 3j
I am registering a batch of 500 transactions in a java application with web3j and after a while it gives me this error:
java.lang.RuntimeException: Error processing transaction request: replacement ...
0
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1answer
54 views
Where is the ethLogObservable method in Web3j?
I can´t find where is the Web3j ethLogObservable method. I can´t find in GitHub repo
0
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1answer
62 views
Recover solidity funcion event in web3j
EthFilter filter = new EthFilter(DefaultBlockParameterName.EARLIEST, DefaultBlockParameterName.LATEST, userContract.getContractAddress().substring(2));
I am trying to recover the event response that ...
1
vote
1answer
101 views
Error processing transaction request: sender doesn't have enough funds to send tx
In a Java project im testing the web3j library. there I have a method that generate a new account to the blockchain
public String url = "http://localhost:7545/";
public Admin admin = Admin.build(new ...
1
vote
1answer
114 views
How to change the nonce between transactions in web3j?
I have this line of code where it registers a transaction in blockchain. And I wanted to know how I can make the nonce different between the transactions?
txhash = careercertificate
....
0
votes
1answer
58 views
Error generating new account with Web3j
Im using the Web3j library to make transactions with my blockchain (Ganache).
I have a method that instantiate a Web3j object and im trying to generate a new account with the given
String url = "...
1
vote
2answers
45 views
java.lang.RuntimeException: Error processing transaction request: replacement transaction underpriced Output from Server
I am generating transactions in a contract I deployed in the Rinkeby network and the first 300 or 400 transactions had no errors and I received the txHash, but when I continued I got this following ...
0
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1answer
35 views
Calling a contract's function with input parameters and passing ether from Geth/Web3
I have deployed a smart contract which basically splits the incoming funds to the specified addresses based on the entered ratio parameter.
Please find the code below:
pragma solidity ^0.4.23;
...
0
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0answers
165 views
Quorum & web3j: Transaction has failed with status: 0x0. Gas used: 0. (not-enough gas?)
I'm doing some play & test with Quorum. I'm using example 7nodes with docker. The network is up and my simple smart contract is deployed with a set and a get function. When I call the set function ...
0
votes
1answer
95 views
ethLogFlowable: how to get event args?
I am using ethLogFlowable to subscribe to an event and read the args of the event, in my case an address and a uint256 value.
I have followed this answer stackExchangeLink, but I am always getting ...
1
vote
1answer
88 views
What does the get Status () method return with a pending state transaction?
If a transaction has a successful state it returns 0x1 but if the transaction has a failed state it returns 0x0. My questions is, what to return when the transaction has a pending status?
public ...
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0answers
101 views
Can anyone help me to access my eth account in metamask using infura in android
My question is about accessing my eth account in metamask using infura in android
0
votes
1answer
101 views
How to Serialize/Deserialize array of bytes?
I'm writing a smart contract and inevitably need to have arrays of bytes as input and output of functions. In remix arrays work just fine but with web3j and web3js there are several issues with arrays ...
0
votes
1answer
55 views
How to apply EthFilter to specific address?
In web3.js, we can apply event filter something like below:
this.event = this.Contract.events.MyEvent({
filter: { address: "0xAccountAddress" },
})
In Web3J, it is translated to
EthFilter ...
0
votes
1answer
161 views
Contract.methods.transfer is a not a function error using web3
Running something simple as this:
Contract = new web3.eth.Contract(this.contractABI, this.contractAddress)
Contract.methods.transfer(toAccount.address, transfferAmount).encodeABI()
Gives me ...
0
votes
0answers
20 views
How to do decoding with web3j?
I am looking for how to decode the input data of a transaction and what I have obtained up to now is in utf-8 and it gives me this data:
"Ã;` Q ò  à                          ...
0
votes
1answer
53 views
Anyone with knowledge in org.web3j.abi.Type Decoder?
I am trying to decode a String with this code that I found but I have not been able to do it.
String to = inputdata.substring(10, 74);
String value = inputdata.substring(74, 138);
Method refMethod = ...
0
votes
0answers
113 views
How to decode the input data in java?
I receive the input data as the image shows. And when I try to decode it with the method:
String inputdata = null;
Optional<Transaction> tx = web3.ethGetTransactionByHash(txHash).send()....
1
vote
1answer
137 views
Get the input data of a transaction with web3j
How can I retrieve transaction details (including the input data) from a txHash using Web3j?
I tried the following method:
public void buscarHhash(Web3j web3, String txHash) throws IOException {
...
1
vote
1answer
161 views
How can I get the TxReceipt of a transaction with web3j?
How can I get the status of a transaction through the TxHash with web3j.
I tried it like this:
public int getEstado(String trx) {
try {
JSONObject json = readJsonFromUrl("https://api....
0
votes
1answer
51 views
How does Ethereum Smart Contract work on Mobile Client
I want to deploy a smart contract on server and interact with it using mobile client. I'm not familiar with how does that work but after some research, I found something like below:
If we compare ...
1
vote
1answer
33 views
How to get the txHash of a transaction?
I have this method where I make a transaction to the network rinkeby, but to know how I can get the hash of the transaction made. I am using java with web3j, in addition to using infura to connect to ...
1
vote
2answers
78 views
Pass specific address in Web3J send method
How to pass specific address in send method in Web3J?
For example, using web3 javascript library, we can pass from address like below.
contract.someMethod().send({ from: this.props.accounts[0] })
...
1
vote
1answer
99 views
Web3j how to get event args when parsing logs?
I'm trying to get an event args in web3j version 4.0.1.
I use the simple syntax which is explained in the docs. I'm getting the log object but there is no args property or such thing in it.
Here is my ...
0
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0answers
18 views
Is still the solidity can not handle prime256v1 operations [duplicate]
I would like to use prime256v1 instead of secp256k1 because prime256v1 is more secures,so can I do that and implement the operations of Blind ECDSA operation verification in solidity?
I mean I want ...
0
votes
2answers
210 views
How to install web3j command line to generate smart contract wrapper
I am trying to generate a simple smart contract wrapper using solc and web3j in ubuntu.
I have downloaded the source as defined in https://docs.web3j.io/command_line.html
Release package can be ...
0
votes
2answers
55 views
transactionHash returned null sometimes when trying to transfer funds using web3j (random behaviour)
I am transferring funds using web3j. However, I was getting transactionHash as null. I checked various posts and found that this issue exist when gas price or gas is bad. I increased both the values, ...
