Service
A service hub is the starting point for most operations you can do inside the node. You are provided with one when a class annotated with CordaService is constructed, and you have access to one inside flows. Most RPCs simply forward to the services found here after some access checking.
The APIs are organised roughly by category, with a few very important top level APIs available on the ServiceHub itself. Inside a flow, it's safe to keep a reference to services found here on the stack: checkpointing will do the right thing (it won't try to serialise the internals of the service).
In unit test environments, some of those services may be missing or mocked out.
Inheritors
Properties
Provides access to storage of arbitrary JAR files (which may contain only data, no code).
The ContractUpgradeService is responsible for securely upgrading contract state objects according to a specified and mutually agreed (amongst participants) contract version.
Provides access to anything relating to cordapps including contract attachment resolution and app context
The DiagnosticsService provides diagnostic level information about the node, including the current version of the node, and the CorDapps currently installed on the node. Note that this information should be used to provide diagnostics only, and no functional decisions should be made based on this.
The configured instance of DigestService which is passed by default to instances of classes like TransactionBuilder and as a parameter to MerkleTree.getMerkleTree(...) method. Default: SHA2_256.
An identity service maintains a directory of parties by their associated distinguished name/public keys and thus supports lookup of a party given its key, or name. The service also manages the certificates linking confidential identities back to the well known identity (i.e. the identity in the network map) of a party.
The key management service is responsible for storing and using private keys to sign things. An implementation of this may, for example, call out to a hardware security module that enforces various auditing and frequency-of-use requirements.
A network map contains lists of nodes on the network along with information about their identity keys, services they provide and host names or IP addresses where they can be connected to. The cache wraps around a map fetched from an authoritative service, and adds easy lookup of the data stored within it. Generally it would be initialised with a specified network map service, which it fetches data from and then subscribes to updates of.
Returns the network parameters the node is operating under.
Provides access to historical network parameters that are used in transaction resolution.
Provides operations to support telemetry and telemetry data between nodes.
A map of hash->tx where tx has been signature/contract validated and the states are known to be correct. The signatures aren't technically needed after that point, but we keep them around so that we can relay the transaction data to other nodes that need it.
The vault service lets you observe, soft lock and add notes to states that involve you or are relevant to your node in some way. Additionally you may query and track states that correspond to various criteria.
Functions
Helper method to append an additional signature for an existing (partially) SignedTransaction using the default identity signing key of the node.
Helper method to append an additional signature to an existing (partially) SignedTransaction.
Return the singleton instance of the given Corda service type. This is a class that is annotated with CordaService and will have automatically been registered by the node.
Return the singleton instance of the given Corda telemetry component type. This is a class that implements TelemetryComponent and will have automatically been registered by the node.
Helper method to create a signature for a FilteredTransaction using the default identity signing key of the node. The legal identity key is used to sign. Additional SignatureMetadata, including the platform version used during signing and the cryptographic signature scheme use, is added to the signature.
Helper method to create a signature for an existing (partially) SignedTransaction using the default identity signing key of the node. The legal identity key is used to sign. Additional SignatureMetadata, including the platform version used during signing and the cryptographic signature scheme use, is added to the signature.
Helper method to create a signature for a FilteredTransaction. Additional SignatureMetadata, including the platform version used during signing and the cryptographic signature scheme use, is added to the signature.
Helper method to create an additional signature for an existing (partially) SignedTransaction. Additional SignatureMetadata, including the platform version used during signing and the cryptographic signature scheme use, is added to the signature.
Exposes a JDBC connection (session) object using the currently configured database. Applications can use this to execute arbitrary SQL queries (native, direct, prepared, callable) against its Node database tables (including custom contract tables defined by extending net.corda.core.schemas.QueryableState).
Creates and tests a ledger built by the passed in dsl.
Returns the Attachment that defines the given StateRef, which must be in the visible subset of the ledger.
Given a StateRef loads the referenced transaction and looks up the specified output ContractState.
Given a Set of StateRef's loads the referenced transaction and looks up the specified output ContractState.
Stores the given SignedTransactions in the local transaction storage and then sends them to the vault for further processing. This is expected to be run within a database transaction.
Stores the given SignedTransactions in the local transaction storage and then sends them to the vault for further processing if notifyVault is true. This is expected to be run within a database transaction.
Stores the given SignedTransactions in the local transaction storage and then sends them to the vault for further processing if statesToRecord is not StatesToRecord.NONE. This is expected to be run within a database transaction.
Allows the registration of a callback that may inform services when the app is shutting down.
Helper method to construct an initial partially signed transaction from a TransactionBuilder using the default identity key contained in the node. The legal identity key is used to sign.
Helper method to construct an initial partially signed transaction from a TransactionBuilder using keys stored inside the node. Signature metadata is added automatically.
Helper method to construct an initial partially signed transaction from a TransactionBuilder using a set of keys all held in this node.
Provides a callback for the Node to customise the LedgerTransaction.
Converts the given StateRef into a StateAndRef object.
Creates a ledger with a single transaction, built by the passed in dsl.
Exposes the Java Persistence API (JPA) to flows via a restricted EntityManager. This method can be used to persist and query entities which inherit from MappedSchema. This is particularly useful if off-ledger data needs to be kept in conjunction with on-ledger state data.