com.r3corda.node.services.api / AbstractNodeService

# AbstractNodeService

`abstract class AbstractNodeService : SingletonSerializeAsToken`

Abstract superclass for services that a node can host, which provides helper functions.

### Constructors

<init> | `AbstractNodeService(net: MessagingService, networkMapCache: NetworkMapCache)` Abstract superclass for services that a node can host, which provides helper functions.

### Properties

net | `val net: MessagingService`
networkMapCache | `val networkMapCache: NetworkMapCache`

### Functions

addMessageHandler | `fun <Q : ServiceRequestMessage, R : Any> addMessageHandler(topic: String, handler: (Q) -> R, exceptionConsumer: (Message, Exception) -> Unit): Unit` Register a handler for a message topic. In comparison to using net.addMessageHandler() this manages a lot of common boilerplate code. Exceptions are caught and passed to the provided consumer. If you just want a simple acknowledgement response with no content, use com.r3corda.core.messaging.Ack. `fun <Q : ServiceRequestMessage, R : Any> addMessageHandler(topic: String, handler: (Q) -> R): Unit` Register a handler for a message topic. In comparison to using net.addMessageHandler() this manages a lot of common boilerplate code. Exceptions are propagated to the messaging layer. If you just want a simple acknowledgement response with no content, use com.r3corda.core.messaging.Ack.

### Inherited Functions

toToken | `open fun toToken(context: SerializeAsTokenContext): SerializationToken`

### Inheritors

InMemoryNetworkMapService | `class InMemoryNetworkMapService : NetworkMapService, AbstractNodeService`
NotaryService | `abstract class NotaryService : AbstractNodeService` A Notary service acts as the final signer of a transaction ensuring two things:
Service | `class Service : AcceptsFileUpload, AbstractNodeService` The Service that wraps Oracle and handles messages/network interaction/request scrubbing.
Service | `class Service : AbstractNodeService` A service that monitors the network for requests for changing the notary of a state, and immediately runs the NotaryChangeProtocol if the auto-accept criteria are met.
Service | `class Service : AbstractNodeService` This class sets up network message handlers for requests from peers for data keyed by hash. It is a piece of simple glue that sits between the network layer and the database layer.