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Smart Contract Deploy

TxTypeSmartContractDeploy deploys a smart contract to the given address. The following changes will be made by this transaction type.

Import necessary classes from the Web3j and kaia libraries(web3j-ext).

Connect to the kaia blockchain using Web3j and specify the URL

Creating sender and fee payer credentials using private keys.

Define gas price and gas limit for the transaction

Get the sender's address from credentials.getAddress()

Getting the nonce for the sender's address

Define contract bytecode, you can get it from compiled solidity code

Get the chain ID from the Kaia network

Initialize variables for transaction parameters

Create a raw transaction

Signing the transaction as sender using KlayTransactionEncoder.signMessage.

Signing the transaction as fee payer using KlayTransactionEncoder.signMessageAsFeePayer.

Sending the signed transaction to kaia network

Getting the transaction receipt

Shutting down the Web3j instance

Decoding the raw transaction to get the transaction type

FeeDelegatedSmartContractDeployExample.java

package org.web3j.example.transactions;

import java.io.IOException;

import java.math.BigInteger;

import org.web3j.crypto.KlayCredentials;

import org.web3j.crypto.KlayRawTransaction;

import org.web3j.crypto.KlayTransactionEncoder;

import org.web3j.crypto.transaction.type.TxType;

import org.web3j.crypto.transaction.type.TxTypeSmartContractDeploy;

import org.web3j.crypto.transaction.type.TxType.Type;

import org.web3j.tx.response.PollingTransactionReceiptProcessor;

import org.web3j.tx.response.TransactionReceiptProcessor;

import org.web3j.example.keySample;

import org.web3j.protocol.core.DefaultBlockParameterName;

import org.web3j.protocol.core.methods.response.EthChainId;

import org.web3j.protocol.core.methods.response.EthSendTransaction;

import org.web3j.protocol.http.HttpService;

import org.web3j.protocol.kaia.Web3j;

import org.web3j.utils.Numeric;

import org.web3j.protocol.kaia.core.method.response.TransactionReceipt;

/**

*

*/

public class FeeDelegatedSmartContractDeployExample implements keySample {

/**

*

*/

public static void run() throws Exception {

Web3j web3j = Web3j.build(new HttpService(keySample.BAOBAB_URL));

KlayCredentials credentials = KlayCredentials.create(keySample.LEGACY_KEY_privkey);

KlayCredentials credentials_feepayer = KlayCredentials.create(keySample.LEGACY_KEY_FEEPAYER_privkey);

BigInteger GAS_PRICE = BigInteger.valueOf(50000000000L);

BigInteger GAS_LIMIT = BigInteger.valueOf(6721950);

String from = credentials.getAddress();

BigInteger nonce = web3j.ethGetTransactionCount(from, DefaultBlockParameterName.LATEST).send()

.getTransactionCount();

String data = "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";

EthChainId EthchainId = web3j.ethChainId().send();

long chainId = EthchainId.getChainId().longValue();

String to = null;

byte[] payload = Numeric.hexStringToByteArray(data);

BigInteger value = BigInteger.ZERO;

BigInteger codeFormat = BigInteger.ZERO;

TxType.Type type = Type.FEE_DELEGATED_SMART_CONTRACT_DEPLOY;

KlayRawTransaction raw = KlayRawTransaction.createTransaction(

type,

nonce,

GAS_PRICE,

GAS_LIMIT,

to,

value,

from,

payload,

codeFormat);

// Sign as sender

byte[] signedMessage = KlayTransactionEncoder.signMessage(raw, chainId, credentials);

// Sign same message as Fee payer

signedMessage = KlayTransactionEncoder.signMessageAsFeePayer(raw, chainId, credentials_feepayer);

String hexValue = Numeric.toHexString(signedMessage);

EthSendTransaction transactionResponse = web3j.ethSendRawTransaction(hexValue).send();

System.out.println("TxHash : \n " + transactionResponse.getResult());

String txHash = transactionResponse.getResult();

int DEFAULT_POLLING_ATTEMPTS_PER_TX_HASH = 40;

int DEFAULT_BLOCK_TIME = 1 * 1000;

long DEFAULT_POLLING_FREQUENCY = DEFAULT_BLOCK_TIME;

TransactionReceiptProcessor transactionReceiptProcessor = new PollingTransactionReceiptProcessor(web3j,

DEFAULT_POLLING_FREQUENCY, DEFAULT_POLLING_ATTEMPTS_PER_TX_HASH);

org.web3j.protocol.core.methods.response.TransactionReceipt ethReceipt = transactionReceiptProcessor

.waitForTransactionReceipt(txHash);

System.out.println("Receipt from eth_getTransactionReceipt : \n" + ethReceipt);

TransactionReceipt receipt = web3j.klayGetTransactionReceipt(txHash).send().getResult();

System.out.println("Receipt from klay_getTransactionReceipt : \n" + receipt);

web3j.shutdown();

TxTypeSmartContractDeploy rawTransaction = TxTypeSmartContractDeploy.decodeFromRawTransaction(signedMessage);

System.out.println("TxType : " + rawTransaction.getKlayType());

}

}

output

❯ java FeeDelegatedSmartContractDeployExample.java