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corda - 如何在一个流程中多次从同一对手方获取签名？

问题描述

我需要实现这样的场景，比如有 CentralParty、PartyA、PartyB。CentralParty 需要发起一个流程，循环中会有 3 笔交易，发起者始终是 Central 方，另一方是 A 方 2 次。

即我正在尝试通过参考以下链接从单个流程中多次从同一交易对手那里收集签名

Corda 在单个流调用中返回多个事务 ()

val flowSessionMap = mutableMapOf<Party, FlowSession>()
var ftx:MutableList<SignedTransaction> = mutableListOf<SignedTransaction>()
var signedTransaction:SignedTransaction

val fullySignedTransactions = matchingStateList.forEach { matchingState ->

    val txCommand = Command(IOUContract.Commands.Matching(), matchingState.participants.map { it.owningKey })
    val txBuilder = TransactionBuilder(notary)
            .addOutputState(matchingState, IOU_CONTRACT_ID)
            .addCommand(txCommand)

    // Stage 2.
    progressTracker.currentStep = VERIFYING_TRANSACTION
    // Verify that the transaction is valid.
    txBuilder.verify(serviceHub)

    // Stage 3.
    progressTracker.currentStep = SIGNING_TRANSACTION
    // Sign the transaction.
    val partSignedTx = serviceHub.signInitialTransaction(txBuilder, ourIdentity.owningKey)


    val sessions = (listOf(PartyA).map { signer ->
        flowSessionMap.getOrPut(signer) {
            initiateFlow(signer)
        }
    })

    val fullySignedTransaction = subFlow(CollectSignaturesInitiatingFlow(
        partSignedTx, sessions)
    )

    signedTransaction = fullySignedTransaction

    ftx.add(signedTransaction)
}

for (transaction in ftx) {
    subFlow(FinalityFlow(transaction))
}

响应者流定义如下：

 class Acceptor(val otherPartyFlow: FlowSession) : FlowLogic<SignedTransaction>() {
    @Suspendable
    override fun call(): SignedTransaction {
        val signTransactionFlow = object : SignTransactionFlow(otherPartyFlow) {
            override fun checkTransaction(stx: SignedTransaction) = requireThat {
                val output = stx.tx.outputs.single().data
                "This must be an Matching State transaction." using (output is MatchingState)
                val Match = output as MatchingState
                "I won't accept IOUs with a value over 100." using (iou.value <= 100)
            }
        }

        return subFlow(signTransactionFlow)
    }
}

其中 CollectSignaturesInitiatingFlow 定义如下：

 @InitiatingFlow
class CollectSignaturesInitiatingFlow(val signedTransaction: SignedTransaction, val sessions: List<FlowSession>): FlowLogic<SignedTransaction>() {
    override fun call(): SignedTransaction {
        return subFlow(CollectSignaturesFlow(signedTransaction, sessions))
    }
}

CollectSignaturesInitiatingFlow 的响应者定义如下：

    @InitiatedBy(CollectSignaturesInitiatingFlow::class)
class CollectSignaturesInitiatingFlowResponder(val otherPartyFlow: FlowSession) : FlowLogic<SignedTransaction>() {
    @Suspendable
    override fun call(): SignedTransaction {
        val signTransactionFlow = object : SignTransactionFlow(otherPartyFlow) {
            override fun checkTransaction(stx: SignedTransaction) {
                TODO("Check the transaction here.")
            }
        }

        return subFlow(signTransactionFlow)
    }
}

在运行相同的代码时，我遇到了一个错误，例如

[WARN ] 15:43:18,817 [Node thread-1] (FlowStateMachineImpl.kt:111) flow.[82900238-9223-4ace-ba78-9ecc45121b11].run - Terminated by unexpected exception {}
net.corda.core.flows.UnexpectedFlowEndException: Counterparty flow on O=PartyA, L=London, C=GB has completed without sending data
    at net.corda.node.services.statemachine.FlowStateMachineImpl.confirmNoError(FlowStateMachineImpl.kt:488) ~[corda-node-3.2-corda.jar:?]
    at net.corda.node.services.statemachine.FlowStateMachineImpl.waitForMessage(FlowStateMachineImpl.kt:444) ~[corda-node-3.2-corda.jar:?]
    at net.corda.node.services.statemachine.FlowStateMachineImpl.sendAndReceiveInternal(FlowStateMachineImpl.kt:385) ~[corda-node-3.2-corda.jar:?]
    at net.corda.node.services.statemachine.FlowStateMachineImpl.sendAndReceive(FlowStateMachineImpl.kt:203) ~[corda-node-3.2-corda.jar:?]
    at net.corda.node.services.statemachine.FlowSessionImpl.sendAndReceive(FlowSessionImpl.kt:29) ~[corda-node-3.2-corda.jar:?]
    at net.corda.node.services.statemachine.FlowSessionImpl.sendAndReceive(FlowSessionImpl.kt:40) ~[corda-node-3.2-corda.jar:?]
    at net.corda.core.flows.DataVendingFlow.sendPayloadAndReceiveDataRequest(SendTransactionFlow.kt:70) ~[corda-core-3.2-corda.jar:?]
    at net.corda.core.flows.DataVendingFlow.call(SendTransactionFlow.kt:48) ~[corda-core-3.2-corda.jar:?]
    at net.corda.core.flows.DataVendingFlow.call(SendTransactionFlow.kt:31) ~[corda-core-3.2-corda.jar:?]
    at net.corda.core.flows.FlowLogic.subFlow(FlowLogic.kt:290) ~[corda-core-3.2-corda.jar:?]
    at net.corda.core.flows.CollectSignatureFlow.call(CollectSignaturesFlow.kt:142) ~[corda-core-3.2-corda.jar:?]
    at net.corda.core.flows.CollectSignatureFlow.call(CollectSignaturesFlow.kt:135) ~[corda-core-3.2-corda.jar:?]
    at net.corda.core.flows.FlowLogic.subFlow(FlowLogic.kt:290) ~[corda-core-3.2-corda.jar:?]
    at net.corda.core.flows.CollectSignaturesFlow.call(CollectSignaturesFlow.kt:114) ~[corda-core-3.2-corda.jar:?]
    at net.corda.core.flows.CollectSignaturesFlow.call(CollectSignaturesFlow.kt:64) ~[corda-core-3.2-corda.jar:?]
    at net.corda.core.flows.FlowLogic.subFlow(FlowLogic.kt:290) ~[corda-core-3.2-corda.jar:?]
    at com.example.flow.ExampleFlowMatching$CollectSignaturesInitiatingFlow.call(ExampleFlowMatching.kt:260) ~[classes/:?]
    at com.example.flow.ExampleFlowMatching$CollectSignaturesInitiatingFlow.call(ExampleFlowMatching.kt:258) ~[classes/:?]
    at net.corda.core.flows.FlowLogic.subFlow(FlowLogic.kt:290) ~[corda-core-3.2-corda.jar:?]
    at com.example.flow.ExampleFlowMatching$ExampleFlowMatchingInitiator.call(ExampleFlowMatching.kt:202) ~[classes/:?]
    at com.example.flow.ExampleFlowMatching$ExampleFlowMatchingInitiator.call(ExampleFlowMatching.kt:45) ~[classes/:?]
    at net.corda.node.services.statemachine.FlowStateMachineImpl.run(FlowStateMachineImpl.kt:96) [corda-node-3.2-corda.jar:?]
    at net.corda.node.services.statemachine.FlowStateMachineImpl.run(FlowStateMachineImpl.kt:44) [corda-node-3.2-corda.jar:?]
    at co.paralleluniverse.fibers.Fiber.run1(Fiber.java:1092) [quasar-core-0.7.9-jdk8.jar:0.7.9]
    at co.paralleluniverse.fibers.Fiber.exec(Fiber.java:788) [quasar-core-0.7.9-jdk8.jar:0.7.9]
    at co.paralleluniverse.fibers.RunnableFiberTask.doExec(RunnableFiberTask.java:100) [quasar-core-0.7.9-jdk8.jar:0.7.9]
    at co.paralleluniverse.fibers.RunnableFiberTask.run(RunnableFiberTask.java:91) [quasar-core-0.7.9-jdk8.jar:0.7.9]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_191]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_191]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) [?:1.8.0_191]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) [?:1.8.0_191]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_191]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_191]
    at net.corda.node.utilities.AffinityExecutor$ServiceAffinityExecutor$1$thread$1.run(AffinityExecutor.kt:62) [corda-node-3.2-corda.jar:?]

标签： corda

解决方案

问题是您在主要流程中启动流程会话ExampleFlowMatchingInitiator，而不是在内部CollectSignaturesInitiatingFlow。

当您调用时initiateFlow，它会在当前InitiatingFlow. 所以当你打电话initiateFlow时ExampleFlowMatchingInitiator，对方会检查它是否有任何响应者注册ExampleFlowMatchingInitiator。它确实 -Acceptor所以它开始一个流程会话来与使用Acceptor.

如果您改为在initiateFlow内部调用CollectSignaturesInitiatingFlow，则交易对手将检查是否有任何响应者注册CollectSignaturesInitiatingFlow。它确实 - - 所以它开始一个流程会话来与使用相反CollectSignaturesInitiatingFlowResponder的交易对手交谈。CollectSignaturesInitiatingFlowResponder

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