import org.web3j.protocol.Web3j;
import org.web3j.protocol.core.methods.response.Web3ClientVersion;
import org.web3j.protocol.http.HttpService;
public class ConnectToNode {
public static void main(String[] args) {
Web3j web3j = Web3j.build(new HttpService("http://localhost:8545"));
try {
Web3ClientVersion web3ClientVersion = web3j.web3ClientVersion().send();
String clientVersion = web3ClientVersion.getWeb3ClientVersion();
System.out.println("Node client version: " + clientVersion);
} catch (Exception e) {
e.printStackTrace();
}
}
}
import org.web3j.protocol.Web3j;
import org.web3j.protocol.core.methods.response.EthBlockNumber;
import org.web3j.protocol.core.methods.response.EthGetBalance;
import org.web3j.protocol.http.HttpService;
import org.web3j.utils.Convert;
import java.math.BigInteger;
public class BlockchainOperations {
public static void main(String[] args) {
Web3j web3j = Web3j.build(new HttpService("http://localhost:8545"));
try {
EthBlockNumber blockNumber = web3j.ethBlockNumber().send();
System.out.println("Current block number: " + blockNumber.getBlockNumber());
String address = "0x1234567890abcdef1234567890abcdef12345678";
EthGetBalance balance = web3j.ethGetBalance(address, blockNumber.getBlockNumber()).send();
BigInteger weiBalance = balance.getBalance();
System.out.println("Balance in Wei: " + weiBalance);
System.out.println("Balance in Ether: " + Convert.fromWei(new BigDecimal(weiBalance), Convert.Unit.ETHER));
} catch (Exception e) {
e.printStackTrace();
}
}
}
