java开发以太坊—不搭节点开发区块链weixin42704356的博客-

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

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 {      @Resource     private IRedisService redisService; private final Map<String, String> headers = new HashMap<>(); private final Map<String, String> querys = headers;      @Override     public 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; }      @Override     public 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; }      @Override     public 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"); }      @Override     public 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"); }      @Override     public BigInteger getTranNum(String address) throws Exception {          StringBuffer path = new StringBuffer("/api?module=proxy&action=eth_getTransactionCount&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 result = json.getString("result"); return new BigInteger(result.substring(2), 16); }      @Override     public 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(); }      @Override     public 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(); }      @Override     public JSONObject tranEth(String from, String to, String privateKey, String num, String gasPrice, String nonce) throws Exception {          String pending = redisService.getString(EthConstant.ADDRESS_TRAN_PENDING_KEY + from);         log.info("pending: " + pending);         List<String> list = new ArrayList<>(); if(pending != null && pending.length() > 50 ){ //有在pending中的交易 要加nonce             list = new ArrayList<>(Arrays.asList(pending.split(","))); for(int i = 0; i < list.size(); i++){                 String hash = list.get(i);                 String pendingStatus = this.checkTranPending(hash); if(StringUtils.isNotBlank(pendingStatus)){                     list.remove(i); } } }         log.info("list size: " + list.size());          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);             nonceMum = nonceMum.add(new BigInteger(String.valueOf(list.size()))); }         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")); }         list.add(hash);         StringBuffer sb = new StringBuffer(""); for(String str: list){             sb.append(str).append(","); }         String val = sb.substring(0, sb.length() -1);         redisService.setString(EthConstant.ADDRESS_TRAN_PENDING_KEY + from, val);          JSONObject jsonObject = new JSONObject();         jsonObject.put("nonce", nonce);         jsonObject.put("hash", hash); return jsonObject; }      @Override     public 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);          String pending = redisService.getString(EthConstant.ADDRESS_TRAN_PENDING_KEY + from);         log.info("pending: " + pending);         List<String> list = new ArrayList<>(); if(pending != null && pending.length() > 50 ){ //有在pending中的交易 要加nonce             list = new ArrayList<>(Arrays.asList(pending.split(","))); for(int i = 0; i < list.size(); i++){                 String hash = list.get(i);                 String pendingStatus = this.checkTranPending(hash); if(StringUtils.isNotBlank(pendingStatus)){                     list.remove(i); } } }         log.info("list size: " + list.size());         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);             nonceMum = nonceMum.add(new BigInteger(String.valueOf(list.size()))); }         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")); }         list.add(hash);         StringBuffer sb = new StringBuffer(""); for(String str: list){             sb.append(str).append(","); }         String val = sb.substring(0, sb.length() -1);         redisService.setString(EthConstant.ADDRESS_TRAN_PENDING_KEY + from, val);          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nonce public 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"; }