com.r3corda.protocols

## Package com.r3corda.protocols

### Types

AbstractStateReplacementProtocol | `abstract class AbstractStateReplacementProtocol<T>` Abstract protocol to be used for replacing one state with another, for example when changing the notary of a state. Notably this requires a one to one replacement of states, states cannot be split, merged or issued as part of these protocols.
BroadcastTransactionProtocol | `class BroadcastTransactionProtocol : ProtocolLogic<Unit>` Notify all involved parties about a transaction, including storing a copy. Normally this would be called via FinalityProtocol.
FetchAttachmentsProtocol | `class FetchAttachmentsProtocol : FetchDataProtocol<Attachment, ByteArray>` Given a set of hashes either loads from from local storage or requests them from the other peer. Downloaded attachments are saved to local storage automatically.
FetchDataProtocol | `abstract class FetchDataProtocol<T : NamedByHash, in W : Any> : ProtocolLogic<Result<T>>` An abstract protocol for fetching typed data from a remote peer.
FetchTransactionsProtocol | `class FetchTransactionsProtocol : FetchDataProtocol<SignedTransaction, SignedTransaction>` Given a set of tx hashes (IDs), either loads them from local disk or asks the remote peer to provide them.
FinalityProtocol | `class FinalityProtocol : ProtocolLogic<Unit>` Finalise a transaction by notarising it, then recording it locally, and then sending it to all involved parties.
NotaryChangeProtocol | `object NotaryChangeProtocol : AbstractStateReplacementProtocol<Party>` A protocol to be used for changing a states Notary. This is required since all input states to a transaction must point to the same notary.
NotaryError | `sealed class NotaryError`
NotaryProtocol | `object NotaryProtocol`
RatesFixProtocol | `open class RatesFixProtocol : ProtocolLogic<Unit>` This protocol queries the given oracle for an interest rate fix, and if it is within the given tolerance embeds the fix in the transaction and then proceeds to get the oracle to sign it. Although the call method combines the query and signing step, you can run the steps individually by constructing this object and then using the public methods for each step.
ResolveTransactionsProtocol | `class ResolveTransactionsProtocol : ProtocolLogic<List<LedgerTransaction>>` This protocol is used to verify the validity of a transaction by recursively checking the validity of all the dependencies. Once a transaction is checked its inserted into local storage so it can be relayed and wont be checked again.
ServiceRequestMessage | `interface ServiceRequestMessage` Abstract superclass for request messages sent to services which expect a reply.
StateReplacementRefused | `class StateReplacementRefused` Thrown when a participant refuses the proposed state replacement
TwoPartyDealProtocol | `object TwoPartyDealProtocol` Classes for manipulating a two party deal or agreement.
TwoPartyTradeProtocol | `object TwoPartyTradeProtocol` This asset trading protocol implements a "delivery vs payment" type swap. It has two parties (B and S for buyer and seller) and the following steps:
ValidatingNotaryProtocol | `class ValidatingNotaryProtocol : Service` A notary commit protocol that makes sure a given transaction is valid before committing it. This does mean that the calling party has to reveal the whole transaction history; however, we avoid complex conflict resolution logic where a party has its input states "blocked" by a transaction from another party, and needs to establish whether that transaction was indeed valid.

### Exceptions

NotaryException | `class NotaryException : Exception`
StateReplacementException | `class StateReplacementException : Exception`

### Functions

sendRequest | `fun <R : Any> MessagingService.sendRequest(topic: String, request: ServiceRequestMessage, target: SingleMessageRecipient, executor: Executor? = null): <ERROR CLASS><R>` Sends a ServiceRequestMessage to target and returns a ListenableFuture of the response.