Building and Verifying Transactions

Building Transactions

Testing your contracts requires transactions. Building a test transaction is similar to a real-world CorDapp. The following sections contain example chains of function calls:

• Java Transactions
• Kotlin Transactions

For more information, see the full Transaction Builder API documentation.

Java Transactions

In Java, you must explicitly get the UTXO Ledger Service and create a transaction builder:

UtxoSignedTransaction issueTransaction = getLedgerService()
                .createTransactionBuilder()
                .addCommand(new SampleCommand.Issue())
                .addOutputState(new SampleState(List.of(aliceKey), 10, aliceKey))
                .setNotary(notaryName)
                .setTimeWindowUntil(Instant.now().plus(Duration.ofSeconds(60)))
                .addSignatories(aliceKey)
                .toSignedTransaction();

Kotlin Transactions

In Kotlin, the transaction building process becomes simpler using the Kotlin DSL:

val issueTransaction = buildTransaction {
    addCommand(new SampleCommand.Issue())
    addOutputState(new SampleState(List.of(aliceKey), 10, aliceKey))
    setNotary(notaryName)
    setTimeWindowUntil(Instant.now().plus(Duration.ofSeconds(60)))
    addSignatories(aliceKey)
}

Verifying Transactions

Once you have built your transaction, you can verify it by calling one of the following assertion functions:

• assertVerifies — use if you are expecting your test to pass the contract validation.
• assertFailsWith — use if you are expecting your test to fail contract validation with an exception message exactly matching the provided string.
• assertFailsWithMessageContaining — use if you are expecting your test to fail contract validation with an error message containing the provided string.