CorDapp Development and Lifecycle BDC Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   What is the purpose of the participants() method in a Corda state?

   • ATo determine the state's unique identifier
   • BTo define the contract that governs the state
   • CTo list the parties that must sign the transaction
   • DTo specify the notary for the state
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2. 17foundation · easy

   Where is a CorDapp JAR typically placed on a Corda node to be installed?

   • AIn the 'plugins' directory
   • BIn the 'lib' directory
   • CIn the 'bin' directory
   • DIn the 'cordapps' directory
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4. 18foundation · easy

   What is the purpose of the 'upgrade' feature in Corda?

   • ATo migrate data to a different database
   • BTo rollback a transaction
   • CTo allow a CorDapp to be replaced with a new version without losing existing states
   • DTo automatically update the Corda platform
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5. 19foundation · easy

   In a standard CorDapp project structure, where are the contract and state classes typically placed?

   • AIn the 'flows' source set
   • BIn the 'services' source set
   • CIn the 'contracts' source set
   • DIn the 'test' source set
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6. 20application · medium

   A logistics CorDapp defines a ShipmentState with a linearId and a status field. A flow updates the status from IN_TRANSIT to DELIVERED. The contract's verify() checks that the output state's status is one step ahead of the input state's status. During testing, the flow fails with a TransactionVerificationException. The developer inspects the transaction and sees the input state's status is IN_TRANSIT and the output state's status is DELIVERED. What is the most likely cause of the failure?

   • AThe flow used the same linearId for the output state, so the contract sees it as a replacement rather than an update.
   • BThe flow did not add the input state to the transaction, so the contract's verify() saw no input and rejected the transition.
   • CThe contract's verify() requires the output status to be exactly one step ahead, but the flow set it to DELIVERED directly from IN_TRANSIT, skipping an intermediate status.
   • DThe output state's contract was not included in the transaction's attachments, so verify() was skipped and the exception came from elsewhere.
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