com.exonum.binding.core.service

Interface Node

All Known Implementing Classes:

NodeFake, NodeProxy

public interface Node

An Exonum node context. Allows to add transactions to Exonum network and get a snapshot of the database state.

Method Summary

Modifier and Type	Method and Description
com.exonum.binding.common.crypto.PublicKey	getPublicKey() Returns the service public key of this node.
com.exonum.binding.common.hash.HashCode	submitTransaction(RawTransaction rawTransaction) Creates a transaction from the given parameters, signs it with the node service key, and then submits it into Exonum network.
<ResultT> ResultT	withSnapshot(Function<Snapshot,ResultT> snapshotFunction) Performs the given function with a snapshot of the current database state.

Method Detail

submitTransaction

com.exonum.binding.common.hash.HashCode submitTransaction(RawTransaction rawTransaction)

Creates a transaction from the given parameters, signs it with the node service key, and then submits it into Exonum network. This node does not execute the transaction immediately, but broadcasts it to all the nodes in the network. Then each node verifies the transaction and, if it is correct, adds it to the pool of unconfirmed transactions. The transaction is executed later asynchronously.

Incorrect transactions (e.g., the payload of which cannot be deserialized by the target service, or which have unknown message id) are rejected by the network.

Be aware that each node has its own service key pair, therefore invocations of this method on different nodes will produce different transactions.

Parameters:

rawTransaction - transaction parameters to include in transaction message

Returns:

hash of the transaction message created by the framework

Throws:

TransactionSubmissionException - if the transaction belongs to an unknown service, or cannot be submitted

NullPointerException - if the transaction is null

See Also:

Blockchain.getTxMessages()

withSnapshot

<ResultT> ResultT withSnapshot(Function<Snapshot,ResultT> snapshotFunction)

Performs the given function with a snapshot of the current database state.

Type Parameters:

ResultT - a type the function returns

Parameters:

snapshotFunction - a function to execute

Returns:

the result of applying the given function to the database state

getPublicKey

com.exonum.binding.common.crypto.PublicKey getPublicKey()

Returns the service public key of this node. The corresponding private key is used for signing transactions in submitTransaction(RawTransaction).

This key is stored under "service_public_key" key in the node configuration file.