kotlin - 接受者如何为状态添加值(value)并发送回发起者

Question

我有方案:

NodeA将状态发送到NodeB(状态:值= 100，CustomerFlag = 0 )

NodeB审查状态/值，并与一起发送批准的标志
签名。(状态:值= 100，CustomerFlag = 1 )

您能帮我如何在NodeB批准/拒绝响应时增加该值吗？

启动器类:

    @Suspendable
    override fun call(): SignedTransaction {

        val notary = serviceHub.networkMapCache.notaryIdentities[0]

        val iouState = IOUState(iouValue, serviceHub.myInfo.legalIdentities.first(), otherParty)
        val txCommand = Command(IOUContract.Commands.Create(), iouState.participants.map { it.owningKey })
        val txBuilder = TransactionBuilder(notary).withItems(StateAndContract(iouState, IOU_CONTRACT_ID), txCommand)

        txBuilder.verify(serviceHub)
        otherPartyFlow.send(partSignedTx)
        val partSignedTx = serviceHub.signInitialTransaction(txBuilder)
        val otherPartyFlow = initiateFlow(otherParty)
        otherPartyFlow.send(partSignedTx)
        return partSignedTx
    }
}

接受者类别:

@InitiatedBy(Initiator::class)
class Acceptor(val otherPartyFlow: FlowSession) : FlowLogic<SignedTransaction>() {
    @Suspendable
    override fun call(): SignedTransaction {

        val receivedData = otherPartyFlow.receive<SignedTransaction>()

        receivedData.unwrap {data -> data }
<<<<< Need help here how to add value and send back >>>>
return updatedData
}
}

Answer 1

您可能需要稍微重新考虑一下流程以使其正常工作。我想说，您最好的选择不是发送已签名的交易给接受方，而是发送IOU状态。然后，Acceptor类可以更改状态中的此标志，并创建/签名事务。然后可以将其发送回启动器类，以验证标志已更改，对事务进行签名，然后将其提交到分类帐。

@Suspendable
override fun call(): SignedTransaction {

    val iouState = IOUState(iouValue, serviceHub.myInfo.legalIdentities.first(), otherParty)

    val otherPartyFlow = initiateFlow(otherParty)
    otherPartyFlow.send(iouState)

    //Receieve back the signedTransaction
    val ptx = otherPartyFlow.receive<SignedTransaction>().unwrap{it}
    val stx = serviceHub.addSignature(ptx)
    //Resolve and commit to the ledger
    subFlow(ResolveTransactionsFlow(stx, otherPartyFlow))
    return subFlow(FinalityFlow(stx))
    }
}

@InitiatedBy(Initiator::class)
class Acceptor(val otherPartyFlow: FlowSession) : FlowLogic<SignedTransaction>() {
    @Suspendable
    override fun call(): SignedTransaction {
        val notary = serviceHub.networkMapCache.notaryIdentities[0]
        val receivedData = otherPartyFlow.receive<IOUState>().unwrap{
            //Do any state verification here
            it
        }
        receivedData.customerFlag = 1

       //Create the txn
       val txCommand = Command(IOUContract.Commands.Create(), receivedData.participants.map { it.owningKey })
       val txBuilder = TransactionBuilder(notary).withItems(StateAndContract(receivedData, IOU_CONTRACT_ID), txCommand)
       //Sign the transaction
       val partSignedTx = serviceHub.signInitialTransaction(txBuilder)
       otherPartyFlow.send(partSignedTx)
       return waitForLedgerCommit(partSignedTx.id)
}
}

您也可以考虑使用signTransactionsFlow收集签名，而不是像上面的Ive那样来回发送stx-请参阅 https://docs.corda.net/flow-state-machines.html