com.exonum.binding.transaction

Interface Transaction

All Known Implementing Classes:

AbstractTransaction

public interface Transaction

An Exonum transaction.

You shall usually extend AbstractTransaction rather than implementing this interface.

See Also:

Exonum Transactions, Exonum Services

Method Summary

Modifier and Type	Method and Description
void	execute(Fork view) Execute the transaction, possibly modifying the blockchain state.
com.exonum.binding.common.message.BinaryMessage	getMessage() Returns this transaction as a binary Exonum message.
default com.exonum.binding.common.hash.HashCode	hash() Returns a hash of this transaction — a SHA-256 hash of the transaction message.
default java.lang.String	info() Returns some information about this transaction in JSON format.
boolean	isValid() Returns true if this transaction is valid: its data holds the invariants, it has a correct signature, etc.

Method Detail

isValid

boolean isValid()

Returns true if this transaction is valid: its data holds the invariants, it has a correct signature, etc.

This method is intended to check the internal consistency of a transaction. You shall not access any external objects in this method (e.g., files, network resources, databases).

If this method returns false, the transaction is considered incorrect, and Exonum discards it. Exonum never records invalid transactions into a blockchain.

execute

void execute(Fork view)
      throws TransactionExecutionException

Execute the transaction, possibly modifying the blockchain state.

Parameters:

view - a database view, which allows to modify the blockchain state

Throws:

TransactionExecutionException - if the transaction cannot be executed normally and has to be rolled back. The transaction will be committed as failed (status "error"), the error code with the optional description will be saved into the storage. The client can request the error code to know the reason of the failure.

java.lang.RuntimeException - if an unexpected error occurs. A correct transaction implementation must not throw such exceptions. The transaction will be committed as failed (status "panic").

info

default java.lang.String info()

Returns some information about this transaction in JSON format.

hash

default com.exonum.binding.common.hash.HashCode hash()

Returns a hash of this transaction — a SHA-256 hash of the transaction message.

getMessage

com.exonum.binding.common.message.BinaryMessage getMessage()

Returns this transaction as a binary Exonum message.