Questions tagged [java]
Java is a general-purpose computer programming language that is concurrent, class-based, object-oriented, and specifically designed to have as few implementation dependencies as possible.
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org.web3j.protocol.exceptions.TransactionException: Transaction receipt was not generated after 600 seconds
Yesterday I could deploy the code successfully, but today onwards I am facing the below error. I tried to reduce/increase the gas fees yet the error is still not resolved.
If anyone is willing to ...
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1
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How to construct an OpenSea order hash in Java?
my code to construct an default order hash as follow:
public class BuildTest {
public static void main(String[] args) throws IOException {
StructuredDataEncoder dataEncoder = new ...
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129
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How to create a Multicall Swap Multihop in JAVA based on Uniswap V3?
Recently Uniswap And Pancakake swap launch thery v3 contracts, so the way of we do a swap changes now.
Is there someone that know how to do that in Java or Kotlin?
I'm asking for a Multihop, because ...
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1
answer
37
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Supporting networks different than Ethereum in Web3j
I'm currently developing Java app that interacts with various networks. I searched it in docs, but without an effect. I would like to know if Web3j supports any other network besides Ethereum like BSC,...
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121
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Help with RPC call on Polygon Network
I've developed an app to generate random wallet addresses and PvtK using a phrase seed file.
My code will check on a list of RPC addresses to verify if some wallet have some balance. The strange is ...
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54
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An API to get wallet balance for all networks
I'm trying to develop a centralizated way to take a wallet addres balance but I need to know if that address have any money in every chain network ( or most of them ).
For now I have to create a WEB3 ...
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2
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159
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indexing all Ethereum fullnode data in a relational database
I want to develop a web app like etherscan.
I realized I have to extract and index all datas in a relational database.
I have chosen Posturesql.
All Datas I want to save are:
block
uncle
transaction ...
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1
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1
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445
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Read USDT transactions and balance on the Tron network(TRC20) with Java (Spring)
How can I read USDT transactions and balance on the Tron network(TRC20) with Java (Spring) for several addresses?
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278
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How to quickly get private keys from mnemonic phrases
I need to get private keys (ethereum/bitcoin and other currencies) from mnemonic phrases as fast as possible. At the moment I am using BitcoinJ library:
Set<BigInteger> privateKeys = new HashSet&...
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140
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Provided address undefined is invalid, the capitalization checksum test failed, or it's an indirect IBAN address which can't be converted
I'm building a Dapp and when i im click the mint button i get this error
Error: Provided address undefined is invalid, the capitalization checksum test failed, or it's an indirect IBAN address which ...
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47
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Managing frequent transactions in Web3j
I've been trying to figure this out to no avail, and hope someone will be able to shed some light and provide some insight as to how I can go at this issue.
I have a backend written in Java Springboot,...
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43
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Send project id from IPFS Infura Java Android
In this tutorial show how in the following code how to connect to the infura project using android devices, but today this code shows the error "project id is required"
Is there a way to ...
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56
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Java IPFS Infura error 401 - Unauthorized
I`m tring to connect with ipfs infura, but send me the response code 401
I created an IPFS project and I have my projectId and secretKey
protected void onCreate(Bundle savedInstanceState) {
...
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Failed to resolve: java-ipfs-http-client:1.3.3
I'm trying to implement IPFS for Java and I came across an error of "Failed to resolve: com.github.ipfs:1.3.3'
build.gradle file
Here i added implementation 'java-ipfs-http-client:1.3.3
plugins {...
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210
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Web3j listening to events with struct as parameter
I've tried to listen my contract event, that contains struct as parameter in my solidity contract:
contract ExampleNFT is ERC721URIStorage, Ownable{
using Counters for Counters.Counter;
Counters....
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208
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How to fix "Unsupported type encountered: tuple" when trying to create smart contract wrapper
I am trying to create Java Wrappers from a Smart Contract, but I always get this error message when trying to create the Java wrappers.
Unsupported type encountered: tuple
I use web3j for generating ...
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Error: Could not find truffle/DeployedAddresses.sol from any sources;
I am working an a blockchain sample project, and I am trying to write a test for my contract and deploy it into Ganache. So, I have to add something like this:
import "truffle/DeployedAddresses....
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1
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124
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Change ganache Owner Account in WEB3J from account[0] to account[1]or account[2]
I'm looking for a way to change owner of the smart contracts in java web3j as we do in web3 javascript using from:
//using account for transaction in javascript
await contract.function(param1, param2, ...
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11
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Need your help guys! [duplicate]
I'm Starting out Solidity, do you have any advice, or learning materials you can share with me.
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185
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Keccak256 hashing of types and values in Java
I'm trying to use the Web3j library (or any other library for that matter) to Keccak256-hash a list of types and a list of values to sign a quote. Specifically, I need to implement the second code ...
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web3j : The term 'web3j' is not recognized as the name of a cmdlet, function, script file, or operable program
Im trying to generate the java code of a contract using web3j but it keeps telling me i dont have web3 installed or its either not working, but i already did npm install web3. also when i check the ...
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1
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202
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Call a solidity function which accepts a struct type using Web3J
We are trying to use web3j for encoding the parameters for calling the solidity functions which are deployed in the private ethereum network. Call is done using JSON-RPC.
We are able to encode the ...
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1
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398
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web3j is not generating struct inside my solidity contract
I have a struct Question in my smart contract. After generating the java wrapper class of my smart contract using web3j, Inside the wrapper class Question is not recognized, looks like web3j is not ...
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1
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42
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Unable to deploy smartcontract using web3j and Rinkbey infura
I'm trying to deploy a smartcontract on Rinkbey. I've followed the official documentation and some tutorials. I implemented the following code in my android studio but contract.deploy returns nothing.
...
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385
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Authorization using Metamask - Signing and validating - can you find any weaknesses in this approach?
I would like to develop a webapp (frontend: ReactJs, backend: Spring Boot) in which users can interact without logging in in the traditional sense of the word (username + password) but instead using ...
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2
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1
answer
432
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Why does Web3j listen to events every 15 seconds?
I use web3j in my Java application. In the smart contract, an event is defined.
event sendEvent(string name);
I subscribed to that event in my app.
contract.sendEventEventFlowable(filter)
....
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1
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3
answers
896
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How to load smart contract with web3j [duplicate]
In the documentation of web3j (https://docs.web3j.io/4.8.7/smart_contracts/interacting_with_smart_contract/)
it has only the example of calling the contract after deploying.
Is there any function in ...
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1
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703
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how to use the value of msg.value and msg.sender of a contract, when a function calls a different contract
I'm studing Solidity and tring to understand how it works.
Starting from Safe Remote Purchase in the "Solidity section by example" the doc (https://docs.soliditylang.org/en/v0.8.12/solidity-...
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26
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Stable release of Hyperledger Besu won't compile
I cloned a fresh copy of Hyperledger Besu from the GitHub repo and when I opened it in Eclipse, it said that there are 148 errors and that the project won't compile.
It also said that there are 108 ...
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1
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332
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org.web3j.protocol.exceptions.ClientConnectionException: Invalid response received: 403; error code: 1020
I have very simple java code using web3j library. I am using mumbai test network for polygon. After calling
String chainId = web3j.netVersion().send().getNetVersion(); line I get error that is written ...
3
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1
answer
2k
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Error while using ERC-20 java library: "only replay-protected (EIP-155) transactions allowed over RPC"
I am trying to make simple transaction using ERC-20 java library. I use mumbai test network for polygon. Code transfers stablecoin from one wallet from another. During approve method call I get ...
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1
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90
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Cannot resolve symbol "ipfs' android
Hello i am trying to send some files from android to IPFS.I am following this article on medium but can't import packages that are required
`
import io.ipfs.api.IPFS;
import io.ipfs.api.MerkleNode;
...
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2
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2
answers
301
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Monitor for all events
It is possible to monitor for all events that happens on Ethereum network or Binance Smart Chain network (BSC). I know that would be a lot of data however I would like later to filter that data.
If ...
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1
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102
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Start and HTTP JSON-RPC geth on android?
Is it possible to change the code in /mobile to allow for a json-rpc api to be spawned on an android?
Or is there something I need to do in Java with the NodeConfig?
I already managed to run a light-...
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0
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490
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Can I get the IPFS hash from file (without uploading it & with java)?
As far as I'm concerned IPFS client uses the resulting SHA-256 hash from files, and also compatible with others, to index them in the IPFS Protocol.
My problem is that I'm not sure how to consistently ...
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0
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77
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Trouble implementing ERC20 payment service in android application
I have been following this tutorial (https://medium.datadriveninvestor.com/a-primer-to-ethereum-token-development-using-java-and-web3j-52b24cc6c403) but seem to keep running into errors when it comes ...
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1
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825
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Web3j, how to correctly byte encode multiple data?
I am interacting with a smart contract and i do not understand correctly how to encode the data using Web3j to interact with the smart contract since I had never interacted with a contract that ...
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177
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Web3j - How to read the contract without credentials?
I'm using Web3j to interact with my deployed smart contract.
I've deployed my contract onto the testnet and can interact with it, however using the generated wrapper code, it requires my wallet.
Web3j ...
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How can I add an option to pay with cryptocurrency in an android app using Java? [duplicate]
For my college assignment I have been tasked with creating an app that among other things allows a user to pay for services using an ICO Token (ERC20 contract), How do I go about doing this? The ...
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1
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857
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How to verify signature in NodeJs via 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):
...
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99
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Encode String to byte[] to invoke method via web3j
I have a method in a contract that receives a bytes object. Web3J generated code in Java translates it to a byte[] object as parameters.
I have the correct String "0x....." thet represents ...
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How can there be multiple FROM addresses in one contract?
As I understood, there cannot be several senders for eth. How to make such a contract?
For example, here is a transaction with several addresses, this is a swap, but it's still not clear how:
https://...
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1
answer
4k
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How do I add minting functions to my webpage?
I'm looking at adding a mint function on my website so that users can directly mint from my website straight to the contract such as this:
https://campfirebear.club/mint
is this just written in JS ? ...
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1
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1k
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Java Keccak 256 hashing implementation of multiple inputs
What's the best way to achieve the equivalent hashing in Java as below in Solidity?
keccak256(abi.encodePacked(arg1,arg2,...))
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443
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how to build Defi app from A to Z
I'm a java developer and a newbie with blockchain. I want to build a simple Defi app with a simple smart contract. please tell me know steps by steps to do that?
how to setup environment?
which the ...
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4
answers
1k
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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 ...
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110
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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] (...
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203
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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 ...
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1
answer
2k
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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",
"...
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2
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960
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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 ...
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