CarIssueFlow.kt

class CarIssueFlow {
    @InitiatingFlow
    @StartableByRPC
    class Initiator(var owningBank: Party, var holdingDealer: Party) : FlowLogic<SignedTransaction?>() {
        @Suspendable
        @Throws(FlowException::class)
        override fun call(): SignedTransaction {
            // find a notary for the transaction
            val notary = serviceHub.networkMapCache.notaryIdentities[0]
            // get a reference to the manufacturer node, the only node that can issue new cars
            val manufacturer = ourIdentity
            // create our car state
            val carState = CarState(owningBank, holdingDealer, manufacturer)
            // build the transaction
            val transactionBuilder = TransactionBuilder(notary)
            // we're manufacturing a new car
            val commandData: CommandData = CarContract.Commands.Issue()
            // add the command and add the expected output of the transaction
            transactionBuilder.addCommand(commandData, manufacturer.owningKey, holdingDealer.owningKey)
            transactionBuilder.addOutputState(carState, CarContract.ID)
            // verify the transaction
            transactionBuilder.verify(serviceHub)
            // initiate the flow and transaction
            val session = initiateFlow(holdingDealer)
            // use corda to collect signatures from all the required signers
            val signedTransaction = serviceHub.signInitialTransaction(transactionBuilder)
            val fullySignedTransaction = subFlow(CollectSignaturesFlow(signedTransaction, listOf(session)))
            return subFlow(FinalityFlow(fullySignedTransaction, listOf(session)))
        }
    }
}