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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.

4
votes
2answers
2k views

Generating Ethereum Private Key,Public Key On Mobile (Android/Java)

I'm looking for a way to generate Ethereum private keys and public keys inside an Android app. I've scavenged the web and ultimately decided to tear apart the code to myetherwallet and import the same ...
1
vote
1answer
3k views

Generate private key and address using web3j

How can i generate private key and address using web3j instead of creating keystore json file
2
votes
1answer
581 views

How could I send transactions continuously by Web3j generated wrapper

I wrote a smart contract and deployed on my private Quorum. I use Web3j to generate java wrapper to call ABIs. For example, // here is a smart contract function function getMoney() external payable ...
1
vote
5answers
700 views

How to invoke functions of Smart Contract from Android phone?

I deployed a smart contract with solidity along with a GUI by Javascript and HTML. This project works well on my computer. Now I want to invoke functions of Smart Contract from Android phone. Is ...
10
votes
5answers
8k views

Can I write and deploy smart contracts in Java language?

I am a Java developer. I want to write a smart contract using Java and deploy it to a private blockchain network. Does Ethereum provide the facility to write smart contracts using Java language? If ...
3
votes
1answer
2k views

Convert String to Bytes32 in web3j?

public String solFunction(String str) { byte[] byteValue = DatatypeConverter.parseHexBinary(str); Bytes32 strInBytes = new Bytes32(byteValue); try { Uint256 value = contract....
2
votes
1answer
2k views

How to decode input data with ABI using java?

There is a tool on npm ethereum-input-data-decoder. And yes, i can read input data as hex byte[] bytes = Hex.decodeHex(transactionReceipt.getInput().substring(2).toCharArray()); System.out.println(...
1
vote
2answers
1k views

How to make transaction using private key and address using web3j

I have a private key and address . Is it possible to make transaction with these parameter using web3j.
5
votes
1answer
2k views

Solidity ecrecover and web3j Sign.signMessage() are not compatible, is it?

Using Web3j to sign and verify a message is fine but when I use the signature generated by Web3j to verify using ecrecover in solidity it doesnot seem to work correctly. The signer address is ...
1
vote
1answer
2k views

Web3j: “Intrinsic gas too low” error when deploying contract in Ethereum from Java

I am a new to Ethereum and Blockchain, I have been trying execution of Contracts using Metamask and Remix using Chrome browser for sometime. I am trying to deploy the same contract from Java using ...
0
votes
1answer
348 views

A bit confused. How do I send ether using Web3j to an address (Android)

EDIT: I am using android platform I think I'm a bit confused conceptually. I would appreciate it if someone could answer these few questions for me as I'm trying to make an app so that I can be ...