org.odpi.openmetadata.frameworks.connectors

Class Connector

java.lang.Object

org.odpi.openmetadata.frameworks.connectors.Connector

Direct Known Subclasses:

ConnectorBase

public abstract class Connector
extends Object

The Connector is the interface for all connector instances. Connectors are client-side interfaces to assets such as data stores, data sets, APIs, analytical functions. They handle the communication with the server that hosts the assets, along with the communication with the metadata server to serve up metadata (properties) about the assets.

Each connector implementation is paired with a connector provider. The connector provider is the factory for connector instances.

The Connector interface defines that a connector instance should be able to return a unique identifier, a connection object and a metadata object called ConnectedAssetProperties.

Each specific implementation of a connector then extends the Connector interface to add the methods to work with the particular type of asset it supports. For example, a JDBC connector would add the standard JDBC SQL interface, the OMRS Connectors add the metadata repository management APIs...

The initialize() method is called by the Connector Provider to set up the connector instance Id and the Connection properties for the connector as part of its construction process.

ConnectedAssetProperties provides descriptive properties about the asset that the connector is accessing. It is supplied to the connector later during its initialization through the initializeConnectedAssetProperties() method. See AssetConsumer OMAS for an example of this.

Both the connector and the connector provider have base classes (ConnectorBase and ConnectorProviderBase respectively) that implement all of the standard methods. The connector developer extends these classes to add the specific methods to manage the asset and configure the base classes.

Constructor Summary

Constructors

Constructor and Description
Connector()

Method Summary

Modifier and Type	Method and Description
abstract void	disconnect() Free up any resources held since the connector is no longer needed.
abstract ConnectedAssetProperties	getConnectedAssetProperties(String userId) Returns the properties that contain the metadata for the asset.
abstract ConnectionProperties	getConnection() Returns the connection object that was used to create the connector instance.
abstract String	getConnectorInstanceId() Returns the unique connector instance id that assigned to the connector instance when it was created.
abstract void	initialize(String connectorInstanceId, ConnectionProperties connection) Call made by the ConnectorProvider to initialize the Connector with the base services.
abstract void	initializeConnectedAssetProperties(ConnectedAssetProperties connectedAssetProperties) Set up the connected asset properties object.
abstract void	start() Indicates that the connector is completely configured and can begin processing.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Connector

public Connector()

Method Detail

initialize

public abstract void initialize(String connectorInstanceId,
                                ConnectionProperties connection)

Call made by the ConnectorProvider to initialize the Connector with the base services.

Parameters:

connectorInstanceId - unique id for the connector instance useful for messages etc

connection - POJO for the configuration used to create the connector.

getConnectorInstanceId

public abstract String getConnectorInstanceId()

Returns the unique connector instance id that assigned to the connector instance when it was created. It is useful for error and audit messages.

Returns:

guid for the connector instance

getConnection

public abstract ConnectionProperties getConnection()

Returns the connection object that was used to create the connector instance. Its contents are never refreshed during the lifetime of a connector instance even if the connection information is updated or removed from the originating metadata repository.

Returns:

connection properties object

initializeConnectedAssetProperties

public abstract void initializeConnectedAssetProperties(ConnectedAssetProperties connectedAssetProperties)

Set up the connected asset properties object. This provides the known metadata properties stored in one or more metadata repositories. The implementation of the connected asset properties object is free to determine when the properties are populated. It may be as lazy as whenever getConnectedAssetProperties() is called.

Parameters:

connectedAssetProperties - properties of the connected asset

getConnectedAssetProperties

public abstract ConnectedAssetProperties getConnectedAssetProperties(String userId)
                                                              throws PropertyServerException,
                                                                     UserNotAuthorizedException

Returns the properties that contain the metadata for the asset. The asset metadata is retrieved from the metadata repository and cached in the ConnectedAssetProperties object each time the getConnectedAssetProperties method is requested by the caller. Once the ConnectedAssetProperties object has the metadata cached, it can be used to access the asset property values many times without a return to the metadata repository. The cache of metadata can be refreshed simply by calling this getConnectedAssetProperties() method again.

Parameters:

userId - userId of requesting user

Returns:

ConnectedAssetProperties connected asset properties

Throws:

PropertyServerException - indicates a problem retrieving properties from a metadata repository

UserNotAuthorizedException - indicates that the user is not authorized to access the asset properties.

start

public abstract void start()
                    throws ConnectorCheckedException

Indicates that the connector is completely configured and can begin processing.

Throws:

ConnectorCheckedException - there is a problem within the connector.

disconnect

public abstract void disconnect()
                         throws ConnectorCheckedException

Free up any resources held since the connector is no longer needed.

Throws:

ConnectorCheckedException - there is a problem within the connector.