java开发以太坊---不搭节点开发

  • readme
  • 直接上代码

readme

以太坊区块链浏览器有提供官方api 已经满足了基本开发需求
api连接

优点： 可以不用搭建节点，节省内存，无须担心节点挂掉影响业务

缺点：官方限制请求接口频率最高为 每秒为5次/ip地址，无法像节点一样监听，需要跑定时任务去查询新的交易

之前写过了搭节点开发的教程 细节和概念不想再说一遍了 直接上代码

交易功能和搭节点有点差别 这里是 构建交易→离线签名→编码→用api接口广播

需要注意的是getTranNum接口有一点不同 还有因为接口请求频率原因 需要加锁及线程休眠的手段来控制频率 这里没有去做 自行处理

maven和jar包去 之前的博客 的3（web3j引入）看，一毛一样 不想再写一次 有不懂的也可以看一下

直接上代码

接口

package com.lim.service;import com.alibaba.fastjson.JSONObject;
import java.math.BigInteger;public interface IAccountService {/*** 离线创建账户* @param pwd* @return*/JSONObject createAccount(String pwd);/*** 获取当前gasPrice* @return*/JSONObject getGasPrice() throws Exception;/*** 检查交易状态 0-正常 1-交易错误* @param hash* @return* @throws Exception*/String checkTran(String hash) throws Exception;/*** 检查交易pending状态 0-失败 1-已完成 null/umpty-pending中* @return* @throws Exception*/String checkTranPending(String hash) throws Exception;/*** 获取地址的交易数量* @param address* @return* @throws Exception*/BigInteger getTranNum(String address) throws Exception;/*** 获取账户eth余额* @param address* @return*/String getEthBalance(String address) throws Exception;/*** 获取账户usdt余额* @param address* @return*/String getUsdtBalance(String address) throws Exception;/*** eth交易* @param from* @param to* @param privateKey* @param num* @param gasPrice* @param nonce* @return* @throws Exception*/JSONObject tranEth(String from, String to, String privateKey, String num, String gasPrice, String nonce) throws Exception;/*** usdt交易* @param from* @param to* @param privateKey* @param num* @param gasPrice* @param gaslimit* @param nonce* @return*/JSONObject tranUsdt(String from, String to, String privateKey, String num, String gasPrice, String gaslimit, String nonce)throws Exception;}

实现类

package com.lim.service.impl;import com.alibaba.fastjson.JSONObject;
import com.lim.eth.EthConstant;
import com.lim.redis.IRedisService;
import com.lim.service.IAccountService;
import com.lim.util.HttpUtils;
import io.github.novacrypto.bip39.MnemonicGenerator;
import io.github.novacrypto.bip39.SeedCalculator;
import io.github.novacrypto.bip39.Words;
import io.github.novacrypto.bip39.wordlists.English;
import io.github.novacrypto.hashing.Sha256;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.HttpResponse;
import org.apache.http.util.EntityUtils;
import org.springframework.stereotype.Service;
import org.web3j.abi.FunctionEncoder;
import org.web3j.abi.datatypes.Address;
import org.web3j.abi.datatypes.Function;
import org.web3j.abi.datatypes.generated.Uint256;
import org.web3j.crypto.*;
import org.web3j.utils.Convert;
import org.web3j.utils.Numeric;
import javax.annotation.Resource;
import java.math.BigInteger;
import java.security.SecureRandom;
import java.util.*;@Slf4j
@Service
public class EAccountServiceImpl implements IAccountService {@Resourceprivate IRedisService redisService;private final Map<String, String> headers = new HashMap<>();private final Map<String, String> querys = headers;@Overridepublic JSONObject createAccount(String pwd) {StringBuilder sb = new StringBuilder();byte[] entropy = new byte[Words.TWELVE.byteLength()];new SecureRandom().nextBytes(entropy);new MnemonicGenerator(English.INSTANCE).createMnemonic(entropy, sb::append);String mnemonic = sb.toString();List mnemonicList = Arrays.asList(mnemonic.split(" "));byte[] seed = new SeedCalculator().withWordsFromWordList(English.INSTANCE).calculateSeed(mnemonicList, pwd);ECKeyPair ecKeyPair = ECKeyPair.create(Sha256.sha256(seed));String privateKey = ecKeyPair.getPrivateKey().toString(16);String publicKey = ecKeyPair.getPublicKey().toString(16);String address = "0x" + Keys.getAddress(publicKey);JSONObject json = new JSONObject();json.put("privateKey", privateKey);json.put("publicKey", publicKey);json.put("address", address);return json;}@Overridepublic JSONObject getGasPrice() throws Exception {StringBuffer path = new StringBuffer("/api?module=gastracker&action=gasoracle&apikey=").append(EthConstant.ETHERSCAN_API_KEY);HttpResponse response = HttpUtils.doGet("https://api.etherscan.io", path.toString(), "GET", headers, querys);String res = EntityUtils.toString(response.getEntity());JSONObject json = JSONObject.parseObject(res);String status = json.getString("status");if(!status.equals("1")){throw new Exception(json.getString("message"));}JSONObject resJson = json.getJSONObject("result");return resJson;}@Overridepublic String checkTran(String hash) throws Exception {StringBuffer path = new StringBuffer("/api?module=transaction&action=getstatus&txhash=").append(hash).append("&apikey=").append(EthConstant.ETHERSCAN_API_KEY);HttpResponse response = HttpUtils.doGet("https://api.etherscan.io", path.toString(), "GET", headers, querys);String res = EntityUtils.toString(response.getEntity());JSONObject json = JSONObject.parseObject(res);String status = json.getString("status");if(!status.equals("1")){throw new Exception(json.getString("message"));}JSONObject resJson = json.getJSONObject("result");return resJson.getString("isError");}@Overridepublic String checkTranPending(String hash) throws Exception {StringBuffer path = new StringBuffer("/api?module=transaction&action=gettxreceiptstatus&txhash=").append(hash).append("&apikey=").append(EthConstant.ETHERSCAN_API_KEY);HttpResponse response = HttpUtils.doGet("https://api.etherscan.io", path.toString(), "GET", headers, querys);String res = EntityUtils.toString(response.getEntity());JSONObject json = JSONObject.parseObject(res);String status = json.getString("status");if(!status.equals("1")){throw new Exception(json.getString("message"));}JSONObject resJson = json.getJSONObject("result");return resJson.getString("status");}@Overridepublic BigInteger getTranNum(String address) throws Exception {//注意这里api上是tag=lasted 是查不到pending中的交易的StringBuffer path = new StringBuffer("/api?module=proxy&action=eth_getTransactionCount&address=").append(address).append("&tag=pending&apikey=").append(EthConstant.ETHERSCAN_API_KEY);HttpResponse response = HttpUtils.doGet("https://api.etherscan.io", path.toString(), "GET", headers, querys);String res = EntityUtils.toString(response.getEntity());JSONObject json = JSONObject.parseObject(res);String result = json.getString("result");return new BigInteger(result.substring(2), 16);}@Overridepublic String getEthBalance(String address) throws Exception {StringBuffer path = new StringBuffer("/api?module=account&action=balance&address=").append(address).append("&tag=latest&apikey=").append(EthConstant.ETHERSCAN_API_KEY);HttpResponse response = HttpUtils.doGet("https://api.etherscan.io", path.toString(), "GET", headers, querys);String res = EntityUtils.toString(response.getEntity());JSONObject json = JSONObject.parseObject(res);String status = json.getString("status");if(!status.equals("1")){throw new Exception(json.getString("message"));}String num = json.getString("result");return Convert.fromWei(num, Convert.Unit.ETHER).toString();}@Overridepublic String getUsdtBalance(String address) throws Exception {StringBuffer path = new StringBuffer("/api?module=account&action=tokenbalance&contractaddress=").append(EthConstant.CONTRACTA_DDRESS).append("&address=").append(address).append("&tag=latest&apikey=").append(EthConstant.ETHERSCAN_API_KEY);HttpResponse response = HttpUtils.doGet("https://api.etherscan.io", path.toString(), "GET", headers, querys);String res = EntityUtils.toString(response.getEntity());JSONObject json = JSONObject.parseObject(res);String status = json.getString("status");if(!status.equals("1")){throw new Exception(json.getString("message"));}String num = json.getString("result");return Convert.fromWei(num, Convert.Unit.MWEI).toString();}@Overridepublic JSONObject tranEth(String from, String to, String privateKey, String num, String gasPrice, String nonce) throws Exception {BigInteger gasPriceNum = null;if(StringUtils.isNotBlank(gasPrice) && new BigInteger(gasPrice).compareTo(new BigInteger("1")) >= 0){gasPriceNum = Convert.toWei(gasPrice, Convert.Unit.GWEI).toBigInteger();} else {gasPriceNum = Convert.toWei(getGasPrice().getString("ProposeGasPrice"), Convert.Unit.GWEI).toBigInteger();}BigInteger nonceMum = null;if(StringUtils.isNotBlank(nonce) && new BigInteger(nonce).compareTo(new BigInteger("0")) >= 0  ){nonceMum = new BigInteger(nonce);} else {nonceMum = this.getTranNum(from);}RawTransaction rawTransaction = RawTransaction.createEtherTransaction( nonceMum, gasPriceNum, new BigInteger("21000"), to,Convert.toWei(num, Convert.Unit.ETHER).toBigInteger());Credentials credentials = Credentials.create(privateKey);byte[] signedMessage = TransactionEncoder.signMessage(rawTransaction, credentials);String hexValue = Numeric.toHexString(signedMessage);StringBuffer path = new StringBuffer("/api?module=proxy&action=eth_sendRawTransaction&hex=").append(hexValue).append("&apikey=").append(EthConstant.ETHERSCAN_API_KEY);HttpResponse response = HttpUtils.doGet("https://api.etherscan.io", path.toString(), "GET", headers, querys);String res = EntityUtils.toString(response.getEntity());JSONObject json = JSONObject.parseObject(res);log.info(json.toString());String hash = json.getString("result");if(StringUtils.isBlank(hash)){throw new Exception(json.getJSONObject("error").getString("message"));}JSONObject jsonObject = new JSONObject();jsonObject.put("nonce", nonce);jsonObject.put("hash", hash);return jsonObject;}@Overridepublic JSONObject tranUsdt(String from, String to, String privateKey, String num, String gasPrice, String gaslimit, String nonce) throws Exception {BigInteger tranNum = Convert.toWei(num, Convert.Unit.MWEI).toBigInteger();Function function = new Function("transfer",Arrays.asList( new Address(to), new Uint256(tranNum) ), Collections.emptyList());String encodeFunction = FunctionEncoder.encode(function);BigInteger gasPriceNum = null;if(StringUtils.isNotBlank(gasPrice) && new BigInteger(gasPrice).compareTo(new BigInteger("1")) >= 0){gasPriceNum = Convert.toWei(gasPrice, Convert.Unit.GWEI).toBigInteger();} else {gasPriceNum = Convert.toWei(getGasPrice().getString("ProposeGasPrice"), Convert.Unit.GWEI).toBigInteger();}BigInteger gasLimitNum = new BigInteger("100000");if(StringUtils.isNotBlank(gaslimit) && new BigInteger(gaslimit).compareTo(new BigInteger("21000")) >= 0){gasLimitNum = new BigInteger(gaslimit);}BigInteger nonceMum = null;if(StringUtils.isNotBlank(nonce) && new BigInteger(nonce).compareTo(new BigInteger("0")) >= 0  ){nonceMum = new BigInteger(nonce);} else {nonceMum = this.getTranNum(from);}RawTransaction rawTransaction = RawTransaction.createTransaction( nonceMum, gasPriceNum, gasLimitNum, EthConstant.CONTRACTA_DDRESS, encodeFunction);Credentials credentials = Credentials.create(privateKey);byte[] signedMessage = TransactionEncoder.signMessage(rawTransaction, credentials);String hexValue = Numeric.toHexString(signedMessage);StringBuffer path = new StringBuffer("/api?module=proxy&action=eth_sendRawTransaction&hex=").append(hexValue).append("&apikey=").append(EthConstant.ETHERSCAN_API_KEY);HttpResponse response = HttpUtils.doGet("https://api.etherscan.io", path.toString(), "GET", headers, querys);String res = EntityUtils.toString(response.getEntity());JSONObject json = JSONObject.parseObject(res);log.info(json.toString());String hash = json.getString("result");if(StringUtils.isBlank(hash)){throw new Exception(json.getJSONObject("error").getString("message"));}JSONObject jsonObject = new JSONObject();jsonObject.put("nonce", nonceMum);jsonObject.put("hash", hash);return jsonObject;}
}

http工具类

package com.lim.util;import org.apache.commons.lang3.StringUtils;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;public class HttpUtils {public static HttpResponse doGet(String host, String path, String method, Map<String, String> headers, Map<String, String> querys)throws Exception {       HttpClient httpClient = wrapClient(host);HttpGet request = new HttpGet(buildUrl(host, path, querys));for (Map.Entry<String, String> e : headers.entrySet()) {request.addHeader(e.getKey(), e.getValue());}return httpClient.execute(request);}public static HttpResponse doPost(String host, String path, String method, Map<String, String> headers, Map<String, String> querys, Map<String, String> bodys)throws Exception {        HttpClient httpClient = wrapClient(host);HttpPost request = new HttpPost(buildUrl(host, path, querys));for (Map.Entry<String, String> e : headers.entrySet()) {request.addHeader(e.getKey(), e.getValue());}if (bodys != null) {List<NameValuePair> nameValuePairList = new ArrayList<NameValuePair>();for (String key : bodys.keySet()) {nameValuePairList.add(new BasicNameValuePair(key, bodys.get(key)));}UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(nameValuePairList, "utf-8");formEntity.setContentType("application/x-www-form-urlencoded; charset=UTF-8");request.setEntity(formEntity);}return httpClient.execute(request);}private static String buildUrl(String host, String path, Map<String, String> querys) throws UnsupportedEncodingException {StringBuilder sbUrl = new StringBuilder();sbUrl.append(host);if (!StringUtils.isBlank(path)) {sbUrl.append(path);}if (null != querys) {StringBuilder sbQuery = new StringBuilder();for (Map.Entry<String, String> query : querys.entrySet()) {if (0 < sbQuery.length()) {sbQuery.append("&");}if (StringUtils.isBlank(query.getKey()) && !StringUtils.isBlank(query.getValue())) {sbQuery.append(query.getValue());}if (!StringUtils.isBlank(query.getKey())) {sbQuery.append(query.getKey());if (!StringUtils.isBlank(query.getValue())) {sbQuery.append("=");sbQuery.append(URLEncoder.encode(query.getValue(), "utf-8"));}}}if (0 < sbQuery.length()) {sbUrl.append("?").append(sbQuery);}}return sbUrl.toString();}private static HttpClient wrapClient(String host) {HttpClient httpClient = new DefaultHttpClient();if (host.startsWith("https://")) {sslClient(httpClient);}return httpClient;}private static void sslClient(HttpClient httpClient) {try {SSLContext ctx = SSLContext.getInstance("TLS");X509TrustManager tm = new X509TrustManager() {public X509Certificate[] getAcceptedIssuers() {return null;}public void checkClientTrusted(X509Certificate[] xcs, String str) {}public void checkServerTrusted(X509Certificate[] xcs, String str) {}};ctx.init(null, new TrustManager[] { tm }, null);SSLSocketFactory ssf = new SSLSocketFactory(ctx);ssf.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);ClientConnectionManager ccm = httpClient.getConnectionManager();SchemeRegistry registry = ccm.getSchemeRegistry();registry.register(new Scheme("https", 443, ssf));} catch (KeyManagementException ex) {throw new RuntimeException(ex);} catch (NoSuchAlgorithmException ex) {throw new RuntimeException(ex);}}
}

常量类

package com.lim.eth;public class EthConstant {//redis key 存储账户地址的pending交易集 用于计算noncepublic static final String ADDRESS_TRAN_PENDING_KEY = "address.tran.pending.key-";//etherscan api秘钥public static final String ETHERSCAN_API_KEY = "******自己申请的秘钥******";//ERC20_USDT合约地址public static final String CONTRACTA_DDRESS = "0xdac17f958d2ee523a2206206994597c13d831ec7";}

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