CorDapp Development and Lifecycle BDC Practice Questions (Page 7)

Questions 31–35

1. 31application · medium

   A developer is implementing a contract for a loan state. The contract must ensure that the loan amount is positive and that the borrower and lender are not the same party. Which approach should the developer take?

   • AImplement the checks in the responder flow
   • BImplement the checks in the flow that builds the transaction
   • CImplement the verify method to check the loan amount and the participants list
   • DImplement the checks in the state's constructor
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2. 32application · medium

   A Corda developer is writing a flow that will create a new trade state between two parties. The flow must ensure that both parties sign the transaction before it is recorded. Which flow implementation step is required to achieve this?

   • ACall FinalityFlow directly with the transaction and the list of required signers
   • BUse the transaction builder to add the state and then call SignTransactionFlow
   • CCall CollectSignaturesFlow with the transaction and then FinalityFlow
   • DCall ReceiveFinalityFlow on the initiating node before building the transaction
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4. 33foundation · easy

   Which class do Corda flows typically extend to implement a flow?

   • AFlowLogic
   • BContractState
   • CTransactionBuilder
   • DServiceHub
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5. 34application · medium

   A developer is implementing a contract for a bond state. The contract must ensure that the bond's maturity date is after its issue date. Where should this rule be enforced?

   • AIn the state's constructor
   • BIn the responder flow
   • CIn the flow that creates the state
   • DIn the contract's verify method
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6. 35expert · hard

   A production CorDapp has a contract that validates a TradeState. The team needs to add a new field to the state and update the contract's verify() logic. The network has existing unconsumed states. The team wants to avoid a hard fork and ensure old states remain spendable. What is the recommended approach?

   • ACreate a new state type and write a flow that consumes all old states and issues new ones in a single transaction.
   • BModify the existing contract class in place and redeploy the CorDapp JAR to all nodes.
   • CDeploy a new contract class with a new version and use contract upgrade transactions to migrate existing states.
   • DUse the network's built-in state migration tool to automatically update the contract version.
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