在执行一个 ERC20 智能合约的transfer调用时发生的org.web3j的一个交易错误： org.web3j.protocol.exceptions.TransactionException: Error processing request: unknown transaction。

  Credentials credentials = null;
         try {
             this.initWeb3Client();
             credentials = WalletUtils.loadCredentials(pwd, path);
             MyToken mt =  MyToken.load(ADDRESS,web3j,
                     credentials, BigInteger.valueOf(20_000_000_000L),BigInteger.valueOf(4_300_000L));
             TransactionReceipt tr = oso.transfer(address,value).send();
             System.out.println("hash:"+tr.getTransactionHash());
         } catch (IOException e) {
             e.printStackTrace();
         } catch (CipherException e) {
             e.printStackTrace();
         } catch (Exception e) {
             e.printStackTrace();
         }

交易被成功的提交到了Rinkeby测试链上，但是抛出了这个错误信息：

org.web3j.protocol.exceptions.TransactionException: Error processing request: unknown transaction
    at org.web3j.tx.response.TransactionReceiptProcessor.sendTransactionReceiptRequest(TransactionReceiptProcessor.java:32)
    at org.web3j.tx.response.PollingTransactionReceiptProcessor.getTransactionReceipt(PollingTransactionReceiptProcessor.java:37)
    at org.web3j.tx.response.PollingTransactionReceiptProcessor.waitForTransactionReceipt(PollingTransactionReceiptProcessor.java:29)
    at org.web3j.tx.TransactionManager.processResponse(TransactionManager.java:72)
    at org.web3j.tx.TransactionManager.executeTransaction(TransactionManager.java:51)
    at org.web3j.tx.ManagedTransaction.send(ManagedTransaction.java:70)
    at org.web3j.tx.Contract.executeTransaction(Contract.java:223)
    at org.web3j.tx.Contract.executeTransaction(Contract.java:207)
    at org.web3j.tx.Contract.executeTransaction(Contract.java:201)
    at org.web3j.tx.Contract.lambda$executeRemoteCallTransaction$3(Contract.java:240)
    at org.web3j.protocol.core.RemoteCall.send(RemoteCall.java:30)
    at com.novel.balbit.ports.contract.MyTokenTest.transfer(MyTokenTest.java:358)
    at com.novel.balbit.ports.contract.MyTokenTest.main(MyTokenTest.java:396)

问题可能解决方法

这个问题应该发生在TransactionReceiptProcessor内部。

当调用web3j.ethGetTransactionReceipt(transactionHash).send()时内部会执行waitForTransactionReceipt。

你的节点可能还没有彻底准备好，无法给你提供一个有效的TransactionReceipt。

你可以通过手动构建交易来解决这个问题：

Web3j web3 = Web3j.build(new HttpService());  // defaults to http://localhost:8545/
Credentials credentials = WalletUtils.loadCredentials("password", "/path/to/walletfile");

// get the next available nonce
EthGetTransactionCount ethGetTransactionCount = web3j.ethGetTransactionCount(
             address, DefaultBlockParameterName.LATEST).sendAsync().get();
BigInteger nonce = ethGetTransactionCount.getTransactionCount();

// create our transaction
RawTransaction rawTransaction  = RawTransaction.createEtherTransaction(
             nonce, <gas price>, <gas limit>, <toAddress>, <value>);

// sign & send our transaction
byte[] signedMessage = TransactionEncoder.signMessage(rawTransaction, credentials);
String hexValue = Hex.toHexString(signedMessage);
// FROM here you can get the tx hash.
EthSendTransaction ethSendTransaction = web3j.ethSendRawTransaction(hexValue).send();

虽然可以使用自定义的交易管理器，但尽量尝试更改轮询的次数来增加获得txhash的概率。

   public static final int DEFAULT_POLLING_ATTEMPTS_PER_TX_HASH = 40;
   public static final long DEFAULT_POLLING_FREQUENCY = 1000 * 15;

例如：

new Transfer(client, new ClientTransactionManager(client ,fromAddress, 100))

另外一个明确的方法：

     val txManager  = new RawTransactionManager(client,credentials,100,1000 * 15)
     val transfer   = new Transfer(client,txManager)

     transfer.sendFunds(
         walletAddress,
         amount,
         currency.convert)