net.corda.core.transactions

Class LedgerTransaction

BaseTransaction

net.corda.core.transactions.LedgerTransaction

All Implemented Interfaces:

NamedByHash

public class LedgerTransaction
extends BaseTransaction

A LedgerTransaction is derived from a class WireTransaction. It is the result of doing the following operations:

• Downloading and locally storing all the dependencies of the transaction.

• Resolving the input states and loading them into memory.

• Doing some basic key lookups on the class Commands to see if any keys are from a recognised party, thus converting the class Command objects into class AuthenticatedObject.

• Deserialising the output states.

All the above refer to inputs using a (txhash, output index) pair.

See Also:

class WireTransaction, class Command, class Command, class AuthenticatedObject

Nested Class Summary

Nested Classes

Modifier and Type

Class and Description

static class

LedgerTransaction.InOutGroup<T extends ContractState,K> A set of related inputs and outputs that are connected by some common attributes. An InOutGroup is calculated using groupStates and is useful for handling cases where a transaction may contain similar but unrelated state evolutions, for example, a transaction that moves cash in two different currencies. The numbers must add up on both sides of the transaction, but the values must be summed independently per currency. Grouping can be used to simplify this logic.

Constructor Summary

Constructors

Constructor and Description

LedgerTransaction(java.util.List<? extends net.corda.core.contracts.StateAndRef<?>> inputs, java.util.List<? extends net.corda.core.contracts.TransactionState<? extends net.corda.core.contracts.ContractState>> outputs, java.util.List<? extends net.corda.core.contracts.AuthenticatedObject<? extends net.corda.core.contracts.CommandData>> commands, java.util.List<? extends net.corda.core.contracts.Attachment> attachments, SecureHash id, Party notary, java.util.List<? extends java.security.PublicKey> signers, TimeWindow timeWindow, TransactionType type) A LedgerTransaction is derived from a class WireTransaction. It is the result of doing the following operations:

Method Summary

Modifier and Type	Method and Description
<T extends CommandData> java.util.List<net.corda.core.contracts.Command>	commandsOfType(java.lang.Class<T> clazz) Helper to simplify getting all class Command items with a interface CommandData of a particular class, interface, or base class.
boolean	equals(java.lang.Object other)
<T extends CommandData> java.util.List<net.corda.core.contracts.Command>	filterCommands(java.lang.Class<T> clazz, java.util.function.Predicate<T> predicate) Helper to simplify filtering class Command items according to a Predicate.
<T extends ContractState> java.util.List<net.corda.core.contracts.StateAndRef>	filterInRefs(java.lang.Class<T> clazz, java.util.function.Predicate<T> predicate) Helper to simplify filtering inputs according to a Predicate.
<T extends ContractState> java.util.List<T>	filterInputs(java.lang.Class<T> clazz, java.util.function.Predicate<T> predicate) Helper to simplify filtering inputs according to a Predicate.
<T extends CommandData> Command<T>	findCommand(java.lang.Class<T> clazz, java.util.function.Predicate<T> predicate) Helper to simplify finding a single class Command items according to a Predicate.
<T extends ContractState> StateAndRef<T>	findInRef(java.lang.Class<T> clazz, java.util.function.Predicate<T> predicate) Helper to simplify finding a single input matching a Predicate.
<T extends ContractState> T	findInput(java.lang.Class<T> clazz, java.util.function.Predicate<T> predicate) Helper to simplify finding a single input interface ContractState matching a Predicate.
Attachment	getAttachment(int index) Helper to simplify getting an indexed attachment.
Attachment	getAttachment(SecureHash id) Helper to simplify getting an indexed attachment.
java.util.List<net.corda.core.contracts.Attachment>	getAttachments() A list of
<T extends CommandData> Command<T>	getCommand(int index) Helper to simplify getting an indexed command.
java.util.List<net.corda.core.contracts.AuthenticatedObject>	getCommands() Arbitrary data passed to the program of each input state.
SecureHash	getId() The hash of the original serialised WireTransaction.
ContractState	getInput(int index) Helper to simplify getting an indexed input interface ContractState.
java.util.List<net.corda.core.contracts.ContractState>	getInputStates()
java.util.List<net.corda.core.contracts.StateAndRef>	getInputs() The resolved input states which will be consumed/invalidated by the execution of this transaction.
<T extends ContractState,K> java.util.List<net.corda.core.transactions.LedgerTransaction.InOutGroup>	groupStates(java.lang.Class<T> ofType, kotlin.jvm.functions.Function1<? super T,? extends K> selector) Given a type and a function that returns a grouping key, associates inputs and outputs together so that they can be processed as one. The grouping key is any arbitrary object that can act as a map key (so must implement equals and hashCode).
int	hashCode()
<T extends ContractState> StateAndRef<T>	inRef(int index) Returns the typed input StateAndRef at the specified index
<T extends ContractState> java.util.List<net.corda.core.contracts.StateAndRef>	inRefsOfType(java.lang.Class<T> clazz) Helper to simplify getting all inputs states of a particular class, interface, or base class.
<T extends ContractState> java.util.List<T>	inputsOfType(java.lang.Class<T> clazz) Helper to simplify getting all inputs states of a particular class, interface, or base class.
void	verify() Verifies this transaction and throws an exception if not valid, depending on the type. For general transactions:

Methods inherited from class net.corda.core.transactions.BaseTransaction

checkInvariants, equals, filterOutRefs, filterOutputs, findOutRef, findOutput, getInputs, getMustSign, getNotary, getOutput, getOutputStates, getOutputs, getTimeWindow, getType, hashCode, outRef, outRef, outRefsOfType, outputsOfType, toString

Methods inherited from interface net.corda.core.contracts.NamedByHash

getId

Constructor Detail

LedgerTransaction

public LedgerTransaction(java.util.List<? extends net.corda.core.contracts.StateAndRef<?>> inputs,
                         java.util.List<? extends net.corda.core.contracts.TransactionState<? extends net.corda.core.contracts.ContractState>> outputs,
                         java.util.List<? extends net.corda.core.contracts.AuthenticatedObject<? extends net.corda.core.contracts.CommandData>> commands,
                         java.util.List<? extends net.corda.core.contracts.Attachment> attachments,
                         SecureHash id,
                         Party notary,
                         java.util.List<? extends java.security.PublicKey> signers,
                         TimeWindow timeWindow,
                         TransactionType type)

A LedgerTransaction is derived from a class WireTransaction. It is the result of doing the following operations:

• Downloading and locally storing all the dependencies of the transaction.

• Resolving the input states and loading them into memory.

• Doing some basic key lookups on the class Commands to see if any keys are from a recognised party, thus converting the class Command objects into class AuthenticatedObject.

• Deserialising the output states.

All the above refer to inputs using a (txhash, output index) pair.

Parameters:

inputs - The resolved input states which will be consumed/invalidated by the execution of this transaction.

commands - Arbitrary data passed to the program of each input state.

attachments - A list of interface Attachment objects identified by the transaction that are needed for this transaction to verify.

id - The hash of the original serialised WireTransaction.

See Also:

class WireTransaction, class Command, class Command, class AuthenticatedObject

Method Detail

getInputStates

public java.util.List<net.corda.core.contracts.ContractState> getInputStates()

inRef

public <T extends ContractState> StateAndRef<T> inRef(int index)

Returns the typed input StateAndRef at the specified index

Parameters:

index - The index into the inputs.

Returns:

The class StateAndRef

verify

public void verify()

Verifies this transaction and throws an exception if not valid, depending on the type. For general transactions:

• The contracts are run with the transaction as the input.

• The list of keys mentioned in commands is compared against the signers list.

Throws:

- if anything goes wrong.

equals

public boolean equals(java.lang.Object other)

hashCode

public int hashCode()

groupStates

public <T extends ContractState,K> java.util.List<net.corda.core.transactions.LedgerTransaction.InOutGroup> groupStates(java.lang.Class<T> ofType,
                                                                                                                        kotlin.jvm.functions.Function1<? super T,? extends K> selector)

Given a type and a function that returns a grouping key, associates inputs and outputs together so that they can be processed as one. The grouping key is any arbitrary object that can act as a map key (so must implement equals and hashCode).

The purpose of this function is to simplify the writing of verification logic for transactions that may contain similar but unrelated state evolutions which need to be checked independently. Consider a transaction that simultaneously moves both dollars and euros (e.g. is an atomic FX trade). There may be multiple dollar inputs and multiple dollar outputs, depending on things like how fragmented the owner's vault is and whether various privacy techniques are in use. The quantity of dollars on the output side must sum to the same as on the input side, to ensure no money is being lost track of. This summation and checking must be repeated independently for each currency. To solve this, you would use groupStates with a type of Cash.State and a selector that returns the currency field: the resulting list can then be iterated over to perform the per-currency calculation.

getInput

public ContractState getInput(int index)

Helper to simplify getting an indexed input interface ContractState.

Parameters:

index - the position of the item in the inputs.

Returns:

The class StateAndRef at the requested index

See Also:

interface ContractState

inputsOfType

public <T extends ContractState> java.util.List<T> inputsOfType(java.lang.Class<T> clazz)

Helper to simplify getting all inputs states of a particular class, interface, or base class.

Parameters:

clazz - The class type used for filtering via an Class.isInstance check. clazz must be an extension of interface ContractState.

Returns:

the possibly empty list of inputs matching the clazz restriction.

inRefsOfType

public <T extends ContractState> java.util.List<net.corda.core.contracts.StateAndRef> inRefsOfType(java.lang.Class<T> clazz)

Helper to simplify getting all inputs states of a particular class, interface, or base class.

Parameters:

clazz - The class type used for filtering via an Class.isInstance check. clazz must be an extension of interface ContractState.

Returns:

the possibly empty list of inputs class StateAndRef matching the clazz restriction.

filterInputs

public <T extends ContractState> java.util.List<T> filterInputs(java.lang.Class<T> clazz,
                                                                java.util.function.Predicate<T> predicate)

Helper to simplify filtering inputs according to a Predicate.

Parameters:

clazz - The class type used for filtering via an Class.isInstance check. clazz must be an extension of interface ContractState.

predicate - A filtering function taking a state of type T and returning true if it should be included in the list. The class filtering is applied before the predicate.

Returns:

the possibly empty list of input states matching the predicate and clazz restrictions.

filterInRefs

public <T extends ContractState> java.util.List<net.corda.core.contracts.StateAndRef> filterInRefs(java.lang.Class<T> clazz,
                                                                                                   java.util.function.Predicate<T> predicate)

Helper to simplify filtering inputs according to a Predicate.

Parameters:

predicate - A filtering function taking a state of type T and returning true if it should be included in the list. The class filtering is applied before the predicate.

clazz - The class type used for filtering via an Class.isInstance check. clazz must be an extension of interface ContractState.

Returns:

the possibly empty list of inputs class StateAndRef matching the predicate and clazz restrictions.

findInput

public <T extends ContractState> T findInput(java.lang.Class<T> clazz,
                                             java.util.function.Predicate<T> predicate)

Helper to simplify finding a single input interface ContractState matching a Predicate.

Parameters:

clazz - The class type used for filtering via an Class.isInstance check. clazz must be an extension of ContractState.

predicate - A filtering function taking a state of type T and returning true if this is the desired item. The class filtering is applied before the predicate.

Returns:

the single item matching the predicate.

Throws:

- if no item, or multiple items are found matching the requirements.

See Also:

interface ContractState

findInRef

public <T extends ContractState> StateAndRef<T> findInRef(java.lang.Class<T> clazz,
                                                          java.util.function.Predicate<T> predicate)

Helper to simplify finding a single input matching a Predicate.

Parameters:

clazz - The class type used for filtering via an Class.isInstance check. clazz must be an extension of ContractState.

predicate - A filtering function taking a state of type T and returning true if this is the desired item. The class filtering is applied before the predicate.

Returns:

the single item matching the predicate.

Throws:

- if no item, or multiple items are found matching the requirements.

getCommand

public <T extends CommandData> Command<T> getCommand(int index)

Helper to simplify getting an indexed command.

Parameters:

index - the position of the item in the commands.

Returns:

The Command at the requested index

commandsOfType

public <T extends CommandData> java.util.List<net.corda.core.contracts.Command> commandsOfType(java.lang.Class<T> clazz)

Helper to simplify getting all class Command items with a interface CommandData of a particular class, interface, or base class.

Parameters:

clazz - The class type used for filtering via an Class.isInstance check. clazz must be an extension of interface CommandData.

Returns:

the possibly empty list of commands with interface CommandData values matching the clazz restriction.

See Also:

class Command, interface CommandData

filterCommands

public <T extends CommandData> java.util.List<net.corda.core.contracts.Command> filterCommands(java.lang.Class<T> clazz,
                                                                                               java.util.function.Predicate<T> predicate)

Helper to simplify filtering class Command items according to a Predicate.

Parameters:

clazz - The class type used for filtering via an Class.isInstance check. clazz must be an extension of interface CommandData.

predicate - A filtering function taking a interface CommandData item of type T and returning true if it should be included in the list. The class filtering is applied before the predicate.

Returns:

the possibly empty list of class Command items with interface CommandData values matching the predicate and clazz restrictions.

See Also:

class Command

findCommand

public <T extends CommandData> Command<T> findCommand(java.lang.Class<T> clazz,
                                                      java.util.function.Predicate<T> predicate)

Helper to simplify finding a single class Command items according to a Predicate.

Parameters:

clazz - The class type used for filtering via an Class.isInstance check. clazz must be an extension of interface CommandData.

predicate - A filtering function taking a interface CommandData item of type T and returning true if it should be included in the list. The class filtering is applied before the predicate.

Returns:

the class Command item with interface CommandData values matching the predicate and clazz restrictions.

Throws:

- if no items, or multiple items matched the requirements.

See Also:

class Command

getAttachment

public Attachment getAttachment(int index)

Helper to simplify getting an indexed attachment.

Parameters:

index - the position of the item in the attachments.

Returns:

The Attachment at the requested index.

getAttachment

public Attachment getAttachment(SecureHash id)

Helper to simplify getting an indexed attachment.

Parameters:

id - the SecureHash of the desired attachment.

Returns:

The Attachment with the matching id.

Throws:

- if no item matches the id.

getInputs

public java.util.List<net.corda.core.contracts.StateAndRef> getInputs()

The resolved input states which will be consumed/invalidated by the execution of this transaction.

getCommands

public java.util.List<net.corda.core.contracts.AuthenticatedObject> getCommands()

Arbitrary data passed to the program of each input state.

getAttachments

public java.util.List<net.corda.core.contracts.Attachment> getAttachments()

A list of

interface Attachment objects identified by the transaction that are needed for this transaction to verify.

See Also:

interface Attachment

getId

public SecureHash getId()

The hash of the original serialised WireTransaction.