问题描述
Credentials creds = getCredentialsFromPrivateKey("private-key");
RawTransactionManager manager = new RawTransactionManager(web3j,creds);
String contractAddress = "0x1278f8c858d799fe1010cfc0d1eeb56508243a4d";
BigInteger sum = new BigInteger("10000000000"); // amount you want to send
String data = encodeTransferData(sum);
BigInteger gasPrice = web3j.ethGasPrice().send().getGasPrice();
BigInteger gasLimit = BigInteger.valueOf(120000); // set gas limit here
EthSendTransaction transaction = manager.sendTransaction(gasPrice,gasLimit,contractAddress,data,null);
System.out.println(transaction.getTransactionHash());
它执行正常并且函数运行,但是我不知道如何读取合约给出的输出,我如何读取该输出?
解决方法
以太坊交易哈希是交易的唯一ID。有了这个交易哈希,你就可以从网络上查询交易状态。
底层 JSON-RPC 调用称为 eth_getTransactionReceipt。这是Web3.js documentation。
如果您的智能合约发出事件,您可以also read those。
,这将返回函数调用的十六进制值
"" 私有静态列表 executeCall(Function function) 抛出 IOException { String encodingFunction = FunctionEncoder.encode(function); org.web3j.protocol.core.methods.response.EthCall ethCall = web3j.ethCall( Transaction.createEthCallTransaction( "0x753ebAf6F6D5C2e3E6D469DEc5694Cd3Aa1A0c21","0x47480bac30de77cd030b8a8dad2d6a2ecdb7f27a",编码函数),DefaultBlockParameterName.LATEST) 。发送(); 字符串值 = ethCall.getValue(); System.out.println(value); System.out.println(FunctionReturnDecoder.decode(value,function.getOutputParameters())); return FunctionReturnDecoder.decode(value,function.getOutputParameters()); }""