org.geotools.arcsde.session

Class Command<R>

Object

Command<R>

Direct Known Subclasses:

Commands.CloseConnection, Commands.CloseStateCommand, Commands.CloseStreamCommand, Commands.CommitTransaction, Commands.CreateAndExecuteQueryCommand, Commands.CreateSeRegistrationCommand, Commands.CreateSeStateCommand, Commands.CreateSeTableCommand, Commands.CreateVersionStateCommand, Commands.DescribeTableCommand, Commands.FetchRowCommand, Commands.GetLayerCommand, Commands.GetTableCommand, Commands.GetVersionCommand, Commands.PrepareQueryCommand, GatherCoverageMetadataCommand

public abstract class Command<R>
extends Object

Runnable used to interact with an ArcSDEConnection.

Instances of this class can be sent to Session.issue(Command) in order to be executed. A Command has exclusive access to the connection for the duration of its execute method. This facility is used to prevent a series of complicated locks and try/catch/finally code.

Author:

Jody Garnett

Constructor Summary

Constructors

Constructor and Description
Command()

Method Summary

Modifier and Type	Method and Description
abstract R	execute(ISession session, SeConnection connection) Executed to operate on an SeConnection, a Command is scheduled for execution on a Session.

Methods inherited from class Object

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

Constructor Detail

Command

public Command()

Method Detail

execute

public abstract R execute(ISession session,
                          SeConnection connection)
                   throws SeException,
                          IOException

Executed to operate on an SeConnection, a Command is scheduled for execution on a Session.

Please keep in mind that a Command should be short in duration; you are sharing this SeConnection with other threads.

Parameters:

session - the Session the command is being executed inside

connection - the session's connection, used to interact with ArcSDE

Returns:

the result of the command execution, or null if the command is not meant to return anything (a command meant to return something should fail if not able to)

Throws:

SeException

IOException