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Updates the transaction API page and cookbook.
This commit is contained in:
Joel Dudley
GitHub
@ -28,6 +28,7 @@ import org.jetbrains.annotations.NotNull;
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import java.security.GeneralSecurityException;
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import java.security.PublicKey;
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import java.security.SignatureException;
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import java.time.Duration;
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import java.time.Instant;
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import java.util.List;
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@ -394,15 +395,18 @@ public class FlowCookbookJava {
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----------------------------*/
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progressTracker.setCurrentStep(TX_VERIFICATION);
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// Verifying a transaction will also verify every transaction in the transaction's dependency chain, which will require
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// transaction data access on counterparty's node. The ``SendTransactionFlow`` can be used to automate the sending
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// and data vending process. The ``SendTransactionFlow`` will listen for data request until the transaction
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// is resolved and verified on the other side:
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// Verifying a transaction will also verify every transaction in
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// the transaction's dependency chain, which will require
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// transaction data access on counterparty's node. The
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// ``SendTransactionFlow`` can be used to automate the sending and
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// data vending process. The ``SendTransactionFlow`` will listen
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// for data request until the transaction is resolved and verified
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// on the other side:
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// DOCSTART 12
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subFlow(new SendTransactionFlow(counterparty, twiceSignedTx));
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// Optional request verification to further restrict data access.
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subFlow(new SendTransactionFlow(counterparty, twiceSignedTx){
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subFlow(new SendTransactionFlow(counterparty, twiceSignedTx) {
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@Override
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protected void verifyDataRequest(@NotNull FetchDataFlow.Request.Data dataRequest) {
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// Extra request verification.
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@ -425,41 +429,43 @@ public class FlowCookbookJava {
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List<StateAndRef<DummyState>> resolvedStateAndRef = subFlow(new ReceiveStateAndRefFlow<DummyState>(counterparty));
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// DOCEND 14
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// A ``SignedTransaction`` is a pairing of a ``WireTransaction``
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// with signatures over this ``WireTransaction``. We don't verify
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// a signed transaction per se, but rather the ``WireTransaction``
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// it contains.
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// DOCSTART 31
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WireTransaction wireTx = twiceSignedTx.getTx();
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// DOCEND 31
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// Before we can verify the transaction, we need the
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// ``ServiceHub`` to use our node's local storage to resolve the
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// transaction's inputs and attachments into actual objects,
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// rather than just references. We do this by converting the
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// ``WireTransaction`` into a ``LedgerTransaction``.
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// DOCSTART 32
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LedgerTransaction ledgerTx = wireTx.toLedgerTransaction(getServiceHub());
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// DOCEND 32
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// We can now verify the transaction.
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// DOCSTART 33
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ledgerTx.verify();
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// DOCEND 33
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try {
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// We'll often want to perform our own additional verification
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// too. Just because a transaction is valid based on the contract
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// rules and requires our signature doesn't mean we have to
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// sign it! We need to make sure the transaction represents an
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// agreement we actually want to enter into.
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// DOCSTART 34
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DummyState outputState = (DummyState) wireTx.getOutputs().get(0).getData();
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if (outputState.getMagicNumber() != 777) {
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// ``FlowException`` is a special exception type. It will be
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// propagated back to any counterparty flows waiting for a
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// message from this flow, notifying them that the flow has
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// failed.
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throw new FlowException("We expected a magic number of 777.");
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// We can now verify the transaction to ensure that it satisfies
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// the contracts of all the transaction's input and output states.
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// DOCSTART 33
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twiceSignedTx.verify(getServiceHub());
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// DOCEND 33
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// We'll often want to perform our own additional verification
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// too. Just because a transaction is valid based on the contract
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// rules and requires our signature doesn't mean we have to
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// sign it! We need to make sure the transaction represents an
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// agreement we actually want to enter into.
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// To do this, we need to convert our ``SignedTransaction``
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// into a ``LedgerTransaction``. This will use our ServiceHub
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// to resolve the transaction's inputs and attachments into
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// actual objects, rather than just references.
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// DOCSTART 32
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LedgerTransaction ledgerTx = twiceSignedTx.toLedgerTransaction(getServiceHub());
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// DOCEND 32
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// We can now perform our additional verification.
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// DOCSTART 34
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DummyState outputState = ledgerTx.outputsOfType(DummyState.class).get(0);
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if (outputState.getMagicNumber() != 777) {
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// ``FlowException`` is a special exception type. It will be
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// propagated back to any counterparty flows waiting for a
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// message from this flow, notifying them that the flow has
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// failed.
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throw new FlowException("We expected a magic number of 777.");
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}
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// DOCEND 34
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} catch (GeneralSecurityException e) {
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// Handle this as required.
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}
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// DOCEND 34
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// Of course, if you are not a required signer on the transaction,
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// you have no power to decide whether it is valid or not. If it
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@ -16,7 +16,6 @@ import net.corda.core.node.services.vault.QueryCriteria.VaultQueryCriteria
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import net.corda.core.transactions.LedgerTransaction
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import net.corda.core.transactions.SignedTransaction
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import net.corda.core.transactions.TransactionBuilder
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import net.corda.core.transactions.WireTransaction
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import net.corda.core.utilities.ProgressTracker
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import net.corda.core.utilities.ProgressTracker.Step
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import net.corda.core.utilities.UntrustworthyData
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@ -379,10 +378,13 @@ object FlowCookbook {
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---------------------------**/
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progressTracker.currentStep = TX_VERIFICATION
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// Verifying a transaction will also verify every transaction in the transaction's dependency chain, which will require
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// transaction data access on counterparty's node. The ``SendTransactionFlow`` can be used to automate the sending
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// and data vending process. The ``SendTransactionFlow`` will listen for data request until the transaction
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// is resolved and verified on the other side:
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// Verifying a transaction will also verify every transaction in
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// the transaction's dependency chain, which will require
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// transaction data access on counterparty's node. The
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// ``SendTransactionFlow`` can be used to automate the sending and
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// data vending process. The ``SendTransactionFlow`` will listen
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// for data request until the transaction is resolved and verified
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// on the other side:
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// DOCSTART 12
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subFlow(SendTransactionFlow(counterparty, twiceSignedTx))
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@ -401,7 +403,8 @@ object FlowCookbook {
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val verifiedTransaction = subFlow(ReceiveTransactionFlow(counterparty))
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// DOCEND 13
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// We can also send and receive a `StateAndRef` dependency chain and automatically resolve its dependencies.
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// We can also send and receive a `StateAndRef` dependency chain
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// and automatically resolve its dependencies.
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// DOCSTART 14
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subFlow(SendStateAndRefFlow(counterparty, dummyStates))
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@ -409,24 +412,10 @@ object FlowCookbook {
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val resolvedStateAndRef = subFlow(ReceiveStateAndRefFlow<DummyState>(counterparty))
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// DOCEND 14
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// A ``SignedTransaction`` is a pairing of a ``WireTransaction``
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// with signatures over this ``WireTransaction``. We don't verify
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// a signed transaction per se, but rather the ``WireTransaction``
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// it contains.
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// DOCSTART 31
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val wireTx: WireTransaction = twiceSignedTx.tx
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// DOCEND 31
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// Before we can verify the transaction, we need the
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// ``ServiceHub`` to use our node's local storage to resolve the
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// transaction's inputs and attachments into actual objects,
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// rather than just references. We do this by converting the
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// ``WireTransaction`` into a ``LedgerTransaction``.
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// DOCSTART 32
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val ledgerTx: LedgerTransaction = wireTx.toLedgerTransaction(serviceHub)
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// DOCEND 32
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// We can now verify the transaction.
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// We can now verify the transaction to ensure that it satisfies
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// the contracts of all the transaction's input and output states.
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// DOCSTART 33
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ledgerTx.verify()
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twiceSignedTx.verify(serviceHub)
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// DOCEND 33
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// We'll often want to perform our own additional verification
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@ -434,8 +423,18 @@ object FlowCookbook {
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// rules and requires our signature doesn't mean we have to
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// sign it! We need to make sure the transaction represents an
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// agreement we actually want to enter into.
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// To do this, we need to convert our ``SignedTransaction``
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// into a ``LedgerTransaction``. This will use our ServiceHub
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// to resolve the transaction's inputs and attachments into
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// actual objects, rather than just references.
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// DOCSTART 32
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val ledgerTx: LedgerTransaction = twiceSignedTx.toLedgerTransaction(serviceHub)
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// DOCEND 32
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// We can now perform our additional verification.
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// DOCSTART 34
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val outputState: DummyState = wireTx.outputsOfType<DummyState>().single()
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val outputState: DummyState = ledgerTx.outputsOfType<DummyState>().single()
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if (outputState.magicNumber == 777) {
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// ``FlowException`` is a special exception type. It will be
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// propagated back to any counterparty flows waiting for a
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