Questions tagged [web3j]
Lightweight Java and Android library for integration with Ethereum clients
355
questions
0
votes
1answer
4 views
Invalid parameters: must provide an Ethereum address
Uncaught (in promise)
{code: -32602, message: 'Invalid parameters: must provide an Ethereum address.'}
(anonymous) @ index.js:64
setTimeout (async)
_fireError @ index.js:63
o @ index....
0
votes
1answer
5 views
Unable to resolve host "ropsten.infura.io" android exception [closed]
this code throw an exeption : Unable to resolve host "ropsten.infura.io"
I don't know where is the problem
There is the code :
import androidx.appcompat.app.AppCompatActivity;
import ...
0
votes
1answer
12 views
android web3j.build() error
The problem I am is that web3j's build symbol is not being recognized. It appears even though adding in the dependency does not work.
In the build.gradle I have added the line "implementation ('...
0
votes
0answers
6 views
Can I verify if given address is a correct ETH address using web3j/Java?
Is there a possibility to verify if given String is a correct Ethereum address?
I have found out that there is a possibility to do that using web3js I can do either:
web3.utils.isAddress('...
2
votes
0answers
50 views
+50
How to verify signature on server backend with web3j?
I am sending an EIP_712 signature from metamask to the java backend (web3j) and I need to verify it on backend java application.
In this topics it is discussed the support of EIP-712 in java (web3j):
...
1
vote
1answer
13 views
web3j cant connect to localhost or bsc network
Issue_title
how to connect bsc test network and localhost:8545
Issue_description
here is my load contract code
PerformanceToken contract = PerformanceToken.load(
this.contractAddress, ...
0
votes
0answers
9 views
How to avoid handling private keys when minting tokens using web3j?
I am able to use web3j to successfully mint NFT. However, in this process, I need to provide the public and private keys as credentials.
Web3j web3 = Web3j.build(new HttpService(ENDPOINT));
...
0
votes
0answers
21 views
Minted NFT's in Rinkeby show up automatically in marketplace collection?
I minted a few NFT's in the Rinkeby testnet using web3j.
When I open my OpenSea account I immediately see it in my collection without having to do anything. The same happens when I connected to ...
0
votes
1answer
7 views
compare uint from datestamp always return true
function testDate(uint date1,uint date2)
public
returns (bool)
{
require(date1 == date2,'not same date')
return date1 == date2;
}
let res = await TestSol.testDate.call(‘1630972800’，‘1631145600’)...
0
votes
1answer
46 views
How to send transaction to payable contract on Binance Smart Chain without Metamask
Suppose there is a live contract (on live network, not test network) out there on Binance Smart Chain and it has a payable function that I want to use. I want to use web3 to send a transaction and ...
0
votes
1answer
36 views
web3j - Unable to call a function that returns tuple[]
I am relatively new to interacting with smart contracts in java and I am facing a problem while trying to retrieve a tuple[] returned by the smart contract function. Here is the ABI definition of the ...
0
votes
0answers
15 views
Web3j ws for unconfirmed transactions repeat some transactions
I am running a Geth (1.10.8) node synchronised with Goerli network, and a Java application using web3j (5.0.0) to consume transaction flowables coming from the node.
web3j.pendingTransactionFlowable()....
0
votes
0answers
12 views
Connecting two Ubuntu Virtual machines on private Ethereum network, can't get the two nodes to read each other
I am trying to connect two ubuntu vm as two ethereum nodes using geth. Addpeer doesn't work and bootnode isn't responding to one of the VMs. Note that I ssh accessed the other VM and can telnet the ...
0
votes
1answer
45 views
Get the same result of abi.encode function in Java
let say we have the following function in solidity:
function tryAbiEncode (address _address, uint8 _amount) public pure returns (bytes memory)
{
return abi.encode("\x19Ethereum Signed ...
1
vote
0answers
31 views
Error processing transaction request: Number can only safely store up to 53 bits
I have the following code (in clojure):
212 (def CGP
213 (reify ContractGasProvider
214 (getGasPrice [_ contract-func] (BigInteger. "1"))
215 (getGasLimit [_ contract-func] (...
1
vote
0answers
52 views
Error in Ropsten: The network id specified in the truffle config (3) does not match the one returned by the network (1)
There are similar questions but I could not find the solution. maybe because smart contract tools are developing so fast. here is the setting for ropsten in truffle config.
ropsten: {
...
0
votes
1answer
27 views
transactions signed always reverted
I don't know how to send a signed transaction against a method payable in Ganache, can someone help me???
When I call the method in Remix it works fine but from Java I get the Hash of the transaction ...
0
votes
0answers
67 views
ETH/BSC Transaction subscribtion
Im connecting to BSC websocket with:
let options = {
filter: {
value: [],
},
fromBlock: 0
};
myContract.events.Transfer(options)
.on('data', event => console.log(event))
...
1
vote
1answer
127 views
Encoding ABI function signature in Java using web3j?
Is there a generic way to simply take an ABI function, something like:
{
"name":"foo",
"inputs":{
"interalType":"uint256",
"...
0
votes
1answer
437 views
How to sign transaction from frontend with metamask and then send that signed data to rest api for submitting the transaction?
I have a front end connected with metamask wallet and a rest API layer.
My requirement is to sign the transaction from metamask and then to send the signed transaction to rest api to submit the ...
1
vote
1answer
69 views
Raw transaction with web3j, tx hash is always null
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 ...
0
votes
1answer
68 views
How to access already deployed Smart Contract using Java?
I would like to get information about token. For example total supply and so on. For this I need the contract. However what is the way to actually load it/access it from Java?
Checking examples in ...
1
vote
0answers
58 views
Web3ProviderEngine does not support synchronous requests on deploy to private network
I know there are many similar questions, but I've been through all of them and haven't got the answer I'm looking for.
I'm trying to deploy a smart contract (that's already been compiled and deployed ...
0
votes
0answers
10 views
Can't invoke a method in a public contract from another contract inside a privacy group using web3j
This is the contract that resides in a privacy group:
pragma solidity 0.7.4;
import "./Coin.sol";
contract PrivateTransfer {
Coin coin;
constructor(Coin _coin) {
coin = ...
0
votes
1answer
115 views
Delay between IPC transaction call and submitting to mempool
I encountered a problem, where a web3j transaction was successfully submitted via IPC call and yet, it was not submitted to mempool for another 40 minutes. Etherscan did not show the TX as pending and ...
1
vote
0answers
41 views
How do I get the transfer/transaction history of an erc20 token using web3j givin an address
I am not sure how to view the the txhistory of an erc20 token for a specific address.
I use a java token wrapper for my erc20 toke as below:
public class ERC20 extends Contract {
public static final ...
0
votes
1answer
104 views
How to get Ether in private blockchain?
Fast summary: Need a faucet-like funcionality in my private blockchain to give Ether to the newly on-demand created wallets from Android Dapp.
I'm working in a project where I've deployed a totally ...
5
votes
1answer
1k views
How to point web3j to other networks such as BSC?
I would like to use web3j and to execute the functions of contracts that are found on Binance Smart Chain. How is this done ?
Would it be just
Web3j web3 = Web3j.build(new HttpService("https://...
1
vote
1answer
150 views
Retrieve public key of an address to verify off-chain signatures
I have a question regarding use of keys in Ethereum for signing requests/data OUTSIDE of Ethereum.
Let's say I have a regular Ethereum EOA with an address and keypair. I now want to have a piece of ...
1
vote
0answers
174 views
eth_estimateGas Error when balance of an account < the amount to send in a transaction
I have used the following request to estimate gas in an ETH transaction in Ropsten.
## JSON-RPC over HTTPS POST
curl https://ropsten.infura.io/v3/YOUR-PROJECT-ID \
-X POST \
-H "Content-...
1
vote
1answer
243 views
How to specify Solidity version in web3j?
I have a simple java maven project whose pom.xml looks like:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
...
0
votes
1answer
132 views
Execution Reverted Details
I am writing code in Java and trying to calculated potential gas units, for a function call on my methods.
I am trying to do so by using infura as a provider for my web3 Instance,
and then created a ...
0
votes
1answer
375 views
How do i import my ethereum wallet just using private key?
Help me out how do i resolve the issue of ethereum smartcontract for getting my wallet when i enter my private key in the text area
Use WalletUtils functionality
The WalletUtils class can be used to ...
0
votes
0answers
21 views
Development of ethereum payments system
I'm in need of some help!
I'm developing a project where I'm supposed to implement an ethereum payment system that will then be installed in a point of sale (POS) in a retail store.
The idea is not to ...
1
vote
1answer
1k views
How to use Web3j call Multicall Contract?
I need to use Multi Call contract to merge multiple calls,Its address on the mainnet is 0x2cc8688C5f75E365aaEEb4ea8D6a480405A48D2A
contract Multicall {
struct Call {
address target;
bytes ...
0
votes
0answers
94 views
org.web3j.protocol.exceptions.ClientConnectionException: Invalid response received: okhttp3.internal.http.RealResponseBody
Environment
Android Studio
Infura – Rinkeby test network
Web3J
Metamask
Rinkeby.etherscan.io
I am trying to build an Android app to read and write smart contract by following the medium article:
...
1
vote
2answers
82 views
TransactionException: Cannot unmarshal invalid hex string when deploying contract in web3j
I have a java server that uses web3j library with geth as the provider. When I tried to deploy my contract on my private test net. I got this error:
org.web3j.protocol.exceptions.TransactionException: ...
0
votes
1answer
226 views
Web3j generate command not running
I am trying to generate a java wrapper class for a solidity contract, I have compiled the file and have the abi and bin file, but when I run the command as follows:
web3j solidity generate ...
1
vote
1answer
167 views
web3j command-line does not recognize flags
I am trying to run the command such as
web3j solidity generate -b SimpleBank/SimpleBank.bin -a SimpleBank/SimpleBank.abi -o ~/IdeaProjects/quiknode/src/main/java/ -p com.simplebank
Found here: https:/...
1
vote
1answer
39 views
How to properly close web3 after execution? - Java
Here is what I am trying to do:
String amt = Web3j.build(new HttpService("https://ropsten.infura.io/v3/123blahblah"))
.ethGetBalance("0xblahblah", DefaultBlockParameterName.LATEST)
...
1
vote
0answers
197 views
org.web3j.protocol.exceptions.ClientConnectionException: Invalid response received on web3j on Android
I am trying to execute transactions by calling my RegisterNewUser function in the deployed smart contract through Android and I am using Infura. However, when I run, there is an error as seen below :
...
1
vote
1answer
51 views
Unable to executive function of smart contract on android studio java file
I am trying to execute some functions of my deployed contract in Android Studio through a Java file. I have generated Java Wrapper files. However, when I run Android Studio, there is no data added to ...
0
votes
0answers
123 views
Cannot generate java wrapper class from contract
currently I am trying to generate a java wrapper contract from my smart contract. The command I use is as seen below :
web3j truffle generate --javaTypes C:\Users\name\Documents\test\...
1
vote
0answers
215 views
Verifying ethereum message signatures with java
I am using web3j to verify message signatures but there are some false negative results.
For example this signature should be right, but it seems like the address could not be recovered:
final ...
1
vote
0answers
15 views
Contracts invoked asynchronously are not packaged as transactions [closed]
I use the sendAsync() method to call the contract asynchronously. If I loop through the method several times, without using get(), the number of packaged transactions is less than the number of calls, ...
0
votes
2answers
363 views
Contract Call has been reverted by the EVM with the reason: 'execution aborted (timeout = 5s)'
I defined an array of objects in the Ethereum smart contract. An object is a structure that is inserted into the array every time a function is called.When 80,000 data is inserted, it takes a long ...
4
votes
2answers
1k views
Problems calling Smart Contract function in Java using Web3j
I am rather new to writing/using smart contracts in Java and I am currently trying to use my smart contract. I already wrote and tested it, compiled it, deployed it to Ropsten, and built my Java class ...
1
vote
0answers
97 views
Ethereum account for HD Wallet key generated with xpub key only using bitcoinj
Accordingly to the BIP32/BIP44 specification recommendations I generating HD Wallet addresses using bitcoinj library (DeterministicKey instances) with the path like M/44'/60'/0'/0/0 using xpub key ...
1
vote
1answer
88 views
How to catch a solidity event from Java
I am trying to make a decentralized android application. It is an online two player Tic-Tac-Toe game. I have implemented the back-end with solidity and a part of the front-end in android studio. ...
1
vote
0answers
72 views
smart contract Thether balanceOf method returns 0x
i used web3j-java call Tether contract method balanceOf(the server node is mine , and on ether mainnet),my address has 3USDT,but i call balanceOf , the node returns me 0x as the balance value,it is ...
