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java 开发web3j java 开发以太坊

覃榜言 2022-09-21 阅读 73

目录

​​java 开发web3j​​

​​java 开发以太坊​​

​​web3j.personalUnlockAccount 找不到​​

​​Maven plugins与dependencies的区别​​

java 开发web3j java 开发以太坊_java


java 开发web3j

java 开发以太坊

java 开发web3j java 开发以太坊_以太坊_02


java 开发web3j java 开发以太坊_3c_03


依赖jar:

java 开发web3j java 开发以太坊_以太坊_04


 代码

package eth;


import org.web3j.crypto.Credentials;
import org.web3j.protocol.Web3j;
import org.web3j.protocol.core.DefaultBlockParameterName;
import org.web3j.protocol.core.methods.request.Transaction;
import org.web3j.protocol.core.methods.response.EthBlock;
import org.web3j.protocol.core.methods.response.TransactionReceipt;
import org.web3j.protocol.core.methods.response.Web3ClientVersion;
import org.web3j.protocol.http.HttpService;
import org.web3j.tx.Transfer;
import org.web3j.utils.Convert;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.List;

public class App
{

public static void main( String[] args )
{
try {
//连接以太坊客户端节点,可以是ganache,geth等,注意地址端口和RPC协议(ws ,http)
Web3j web3j = Web3j.build(new HttpService("http://127.0.0.1:7545"));
//获取客户端版本号,通常用来判断是否连接上
Web3ClientVersion web3clientversion = web3j.web3ClientVersion().send();
String clientVersion = web3clientversion.getWeb3ClientVersion();
System.out.println("web3clientVersion : " + clientVersion);
//获取节点上所有的账户,在ganache中,每个账户有100ETH,允许你用上面用户交易
//注意绝大多数以太坊客户端节点不会允许你用它上面的账户交易,你要自己创建钱包(见后面的Cpp类main函数)
List<String> addressList = web3j.ethAccounts().send().getAccounts();
System.out.println("addressList : "+addressList);
//交易前,获取前两个账户余额
BigInteger balance0 = web3j.ethGetBalance(addressList.get(0), DefaultBlockParameterName.LATEST).send().getBalance();
BigInteger balance1 = web3j.ethGetBalance(addressList.get(1), DefaultBlockParameterName.LATEST).send().getBalance();
System.out.println("before Transaction:");
System.out.println("balance0 : " + addressList.get(0) + " : " + balance0);
System.out.println("balance1 : " + addressList.get(1) + " : " + balance1);

//生成交易,参数包括谁发送,发给谁,发多少,给矿工的小费等等,由于ganache允许我们操作它上面的账户,所以不用签名。
BigInteger mynounce = web3j.ethGetTransactionCount(addressList.get(0), DefaultBlockParameterName.LATEST).send().getTransactionCount();
BigInteger gasPrice = web3j.ethGasPrice().send().getGasPrice();
BigInteger gasLimit = BigInteger.valueOf(21000);
BigInteger value = Convert.toWei(BigDecimal.valueOf(0.5), Convert.Unit.ETHER).toBigInteger() ;
Transaction mytesttransaction= Transaction.createEtherTransaction(addressList.get(0),mynounce, gasPrice, gasLimit, addressList.get(1),value);
System.out.println("mytesttransaction : ");
printTransaction(mytesttransaction);
//发送交易,获取交易哈希
String txhash = web3j.ethSendTransaction(mytesttransaction).send().getTransactionHash();
System.out.println("txhash : " + txhash);
//交易对应的收据,这个对于智能合约交易非常有用,对普通交易没多大用
TransactionReceipt transactionReceipt = web3j.ethGetTransactionReceipt(txhash).send().getTransactionReceipt().get();
System.out.println("transactionReceipt : " + transactionReceipt);

//交易后的余额
balance0 = web3j.ethGetBalance(addressList.get(0), DefaultBlockParameterName.LATEST).send().getBalance();
balance1 = web3j.ethGetBalance(addressList.get(1), DefaultBlockParameterName.LATEST).send().getBalance();
System.out.println("after Transaction:");
System.out.println("balance0 : " + addressList.get(0) + " : " + balance0);
System.out.println("balance1 : " + addressList.get(1) + " : " + balance1);

//获取当前最新区块,并获取它上面的所有交易
EthBlock.Block latestBlock = web3j.ethGetBlockByNumber(DefaultBlockParameterName.LATEST, false).send().getBlock();
System.out.println("latestBlock: " + latestBlock.getHash());
//获取区块上的所有交易
List<EthBlock.TransactionResult> txlist = latestBlock.getTransactions();
System.out.println("get TransactionBy Block :" );
for (EthBlock.TransactionResult transactionResult : txlist) {
System.out.println(transactionResult.get());
}
System.out.println("===============");
printTransaction(mytesttransaction);
System.out.println("===============");

} catch (Exception e) {
System.out.println(e);
e.printStackTrace();
}
}
public static void printTransaction(Transaction x) {
//打印交易信息
System.out.println("From:"+x.getFrom());
System.out.println("GasLimit:"+x.getGas());
System.out.println("Nonce:"+x.getNonce());
System.out.println("GasPrice:"+x.getGasPrice());
System.out.println("To:"+x.getTo());
System.out.println("Value:"+x.getValue());
}

}
class Cpp {
public static void main(String[] args) {
try {
Web3j web3j = Web3j.build(new HttpService("http://127.0.0.1:7545"));
//通常情况下,以太坊节点是不会让其他人用它上面的账户,我们要自己创建钱包,用自己的私钥对交易签名,
//下面的私钥是ganache上第一个账户的私钥,虽然交易发起者和上面的交易一样,但两者本质是不同的。
Credentials mysigner = Credentials.create("f6b3f11ac120b04581d0273faeacbed5be08f4a0cdc3ddb82ed522f9a344b350");
List<String> addressList = web3j.ethAccounts().send().getAccounts();
String txhash = Transfer.sendFunds(web3j, mysigner, addressList.get(1), BigDecimal.valueOf(1.0), Convert.Unit.ETHER).send().getTransactionHash();
System.out.println("txhash:"+txhash);
TransactionReceipt receipt = web3j.ethGetTransactionReceipt(txhash).send().getTransactionReceipt().get();
System.out.println(receipt);
} catch


web3j.personalUnlockAccount 找不到

jar 包需要老版本的,现在是新的了 

java 开发web3j java 开发以太坊_java_05


Maven plugins与dependencies的区别

plugins是插件

dependency引入jar包。


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