ResultsetProjectionActivity (OGSA-DAI -- (c) International Business Machines Corporation, 2002-2006, The University of Edinburgh, 2002-2006)

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uk.org.ogsadai.activity.sql
Class ResultsetProjectionActivity

java.lang.Object
  |
  +--uk.org.ogsadai.activity.Activity
        |
        +--uk.org.ogsadai.activity.sql.ResultsetProjectionActivity

public class ResultsetProjectionActivity
extends Activity

A ResultSetProjectionActivity projects a java.sql.ResultsSet input onto a column name or a column index. It should be noted that the projection results are put in the output as databse objects. therefore this activity can not be used as an end-activity.

For information on this activity see the OGSA-DAI user doc: OGSA-DAI/doc/interaction/activities/relational/resultsetProjection.html

Author:: The OGSA-DAI Project Team

Field Summary
`private static java.lang.String`	`COPYRIGHT_NOTICE` Copyright statement
`private boolean`	`isName` Flag to check if a name or an index attribute is provided `true` if its an attribute name
`private static DAILogger`	`LOG` Logger object for logging in this class.
`private int`	`mAttributeIndex` The index of the attribute to project onto
`private java.lang.String`	`mAttributeName` The name of the attribute to project onto
`private BlockReader`	`mInput` Activity input - `java.sql.ResultSet`
`private BlockWriter`	`mOutput` Activity output - `java.lang.Object`s

Fields inherited from class uk.org.ogsadai.activity.Activity

mContext, mExternalInputs, mExternalOutputs, mInternalInputs, mInternalOutputs

Constructor Summary
`ResultsetProjectionActivity(org.w3c.dom.Element element)`

Method Summary
`void`	`initialise()` This method should be overridden by subclasses to perform any initialisation they require before the `process` method invocations begin.
`void`	`processBlock()` Performs an iteration of the processing of an activity.

Methods inherited from class uk.org.ogsadai.activity.Activity

cleanUp, connectsTo, createOutputPipe, getActivityConfiguration, getActivityName, getCause, getName, getObservableStatus, getProperties, getSession, getStatus, hasActivityConfiguration, hasProperties, process, processFirst, setActivityName, setCompleted, setError

Methods inherited from class java.lang.Object

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

Field Detail

COPYRIGHT_NOTICE

private static final java.lang.String COPYRIGHT_NOTICE

See Also:: Constant Field Values

LOG

private static final DAILogger LOG

Logger object for logging in this class.

mInput

private BlockReader mInput

Activity input - java.sql.ResultSet

mOutput

private BlockWriter mOutput

Activity output - java.lang.Objects

mAttributeName

private java.lang.String mAttributeName

The name of the attribute to project onto

mAttributeIndex

private int mAttributeIndex

The index of the attribute to project onto

isName

private boolean isName

Flag to check if a name or an index attribute is provided true if its an attribute name

Constructor Detail

ResultsetProjectionActivity

public ResultsetProjectionActivity(org.w3c.dom.Element element)
                            throws ActivitySpecificationException,
                                   ActivityCreationException

Method Detail

initialise

public void initialise()
                throws ActivitySpecificationException,
                       ActivityExecutionException

Description copied from class: Activity

This method should be overridden by subclasses to perform any initialisation they require before the process method invocations begin. This might be used for setting up convenient fields to reference objects contained in the context. It shouldn't be used for opening resources. That should be done in processFirst.

Overrides:: initialise in class Activity

Throws:: ActivityExecutionException - If some system problem prevents the activity from initialising.; ActivitySpecificationException - If a problem with settings provided by a client prevents the activity from initialising.

processBlock

public void processBlock()

Description copied from class: Activity

Performs an iteration of the processing of an activity. This may involve reading a block of input data and writing a block of output data, or may involve some other kind of processing. When an activity is processed by the OGSA-DAI engine, this method will be invoked repeatedly until the activity either completes or stops due to an error or termination call. An implementation of this method should invoke the setCompleted method to indicate that processing is complete, or the setError method if an error occurs that will prevent the processing from completing.