求解！Transaction，如何生成Data

[antgan]

Data是为了SendTransactionWithPassphrase

[yupnano]

SendTransactionWithPassphrase 不需要data呀。
你是说的 SendRawTransaction 吗？

[antgan]

是的是的！！那个SendRawTransaction的Data怎么来！我试了好多次都不行。

我指的是call contract function

[antgan]

Hope your reply!
几天没睡好！我通过AccountManager生成Address，生成了Sign。然后怎么变成Data

[yupnano]

call conract function 是指的哪个接口呀？
是指的 rpc 的 call 接口吗?
https://github.com/nebulasio/nebulasj/blob/master/src/test/java/io/nebulas/client/TestNebulasClient.java#L39

[antgan]

我指这个testSendRawTransaction的Data。
难道是我理解错了吗。调用contract的方法，并且生效（上链）。需要SendRawTransaction

就像官方的Web-wallet 测试合约一样，点击测试按钮，只是调用call，如果点击部署，会SendRawTransaction，上链。

[antgan]

我是这样的一个应用场景：
我在Java设置了个定时器，定时触发去调用一个Contract里的方法，但是如果单单只是call的话，是无效的。

[yupnano]

我刚找了一下，的确缺少这方面的例子。稍后我会补充上使用示例。
现在你可以尝试这样做，结合TransactionExample.java

Transaction tx = new Transaction(chainID, from, to, value, nonce, payloadType, payload, gasPrice, gasLimit);
manager.signTransaction(tx,passphrase);
byte[] rawData = tx.toProto();

//用下面这条指令得到rawData, 然后就可以用 SendRawTransaction 去发送了.
//需要import io.nebulas.util.ByteUtils;
String rawData = ByteUtils.Base64ToString(rawData);

[antgan]

payloadType, payload分别是什么。PayloadType应该是Call，那payload呢。调用合约的方法

[antgan]

是这个呢？

{"transaction":{"from":"n1LkDi2gGMqPrjYcczUiweyP4RxTB6Go1qS","to":"n1rVLTRxQEXscTgThmbTnn2NqdWFEKwpYUM", "value":"0","nonce":2,"gasPrice":"1000000","gasLimit":"2000000","contract":{"function":"takeout","args":"[50]"}}, "passphrase": "passphrase"}

还是

{"from":"n1LkDi2gGMqPrjYcczUiweyP4RxTB6Go1qS","to":"n1rVLTRxQEXscTgThmbTnn2NqdWFEKwpYUM","value":"0","nonce":3,"gasPrice":"1000000","gasLimit":"2000000","contract":{"function":"balanceOf","args":""}}

[yupnano]

你看一下这个例子，TransactionExample.java，里面有如何构建binary、call、deploy三种类型的transaction。
比如call类型的transaction：

payloadType = Transaction.PayloadType.CALL;
payload = new TransactionCallPayload("function", "").toBytes();
to = Address.ParseFromString("n1g6JZsQS1uRUySdwvuFJ7FYT4dFoyoSN5q");
tx = new Transaction(chainID, from, to, value, nonce, payloadType, payload, gasPrice, gasLimit);

[antgan]

非常感谢！我的问题已经得到解答！今晚试试。

[antgan]

@yupnano Hi, NebulasClient中的SendRawTransaction和使用Grpc 有什么区别？

我已经尝试过使用NebulasClient中的SendRawTransaction， 返回null

private static byte[] passphrase = "passphrase".getBytes();

    private static NebulasClient nebulasClient = HttpNebulasClient.create(Config.API_URL);
    public static void main(String args[]) throws Exception {
        AccountManager manager = new AccountManager();
        NebState nebState = nebulasClient.getNebState().getResult();
        // binary tx
        int chainID = nebState.getChainId(); //1 mainet,1001 testnet, 100 default private
        Address from = manager.newAccount(passphrase);
        //Address to = manager.newAccount("topassphrase".getBytes());
        BigInteger value = new BigInteger("0");
        long nonce = 1; // nonce = from.nonce + 1
        BigInteger gasPrice = new BigInteger("1000000"); // 0 < gasPrice < 10^12
        BigInteger gasLimit = new BigInteger("20000"); // 20000 < gasPrice < 50*10^9
        // call tx
        Transaction.PayloadType payloadType = Transaction.PayloadType.CALL;
        byte[] payload = new TransactionCallPayload("award", "").toBytes();
        // call to = contract address
        Address to = Address.ParseFromString("n1jFA5H9MwvfUCUChdav5DmJz51KDrhC7Bq");
        Transaction tx = new Transaction(chainID, from, to, value, nonce, payloadType, payload, gasPrice, gasLimit);
        manager.signTransaction(tx,passphrase);
        byte[] rawData = tx.toProto();
        // senrawTransaction with @rawData
        // https://github.com/nebulasio/wiki/blob/master/rpc.md#sendrawtransaction
        SendRawTransaction(rawData);
    }

    private static void SendRawTransaction(byte[] data) throws Exception {
        // Channels are secure by default (via SSL/TLS). For the example we disable TLS to avoid
        // needing certificates.
//        ManagedChannel channel = ManagedChannelBuilder.forAddress(Config.API_URL, 8684).usePlaintext().build();
//        Rpc.SendRawTransactionRequest request = Rpc.SendRawTransactionRequest
//                .newBuilder()
//                .setData(ByteString.copyFrom(data))
//                .build();
//
//        ApiServiceGrpc.ApiServiceBlockingStub apiServiceStub = ApiServiceGrpc.newBlockingStub(channel);
//        Rpc.SendTransactionResponse response = apiServiceStub.sendRawTransaction(request);
//        System.out.println(response);

        Response<RawTransaction> rawTransactionResponse = nebulasClient.sendRawTransaction(new SendRawTransactionRequest(ByteUtils.Base64ToString(data)));
        System.out.println(rawTransactionResponse);

    }

Return:

Response(error=null, result=RawTransaction(txHash=null, contractAddress=))

[antgan]

补充一下：如果用Grpc的方式，主网和测试网的地址填什么~