uk.org.ogsadai.activity.sql
Class AbstractSQLActivity

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

Direct Known Subclasses:

AbstractParameterisedSQLActivity, SQLBulkLoadRowSetActivity

public abstract class AbstractSQLActivity

extends Activity

Super-class of SQL activity implementations.

Author:

The OGSA-DAI Project Team.

Field Summary

private static java.lang.String	COPYRIGHT_NOTICE Copyright statement
static java.lang.String	CREATE_DATABASE
static java.lang.String	DROP_DATABASE
static java.lang.String	EXPRESSION Constants for parsing SQL activity XML
private static DAILogger	LOG Logger object for logging in this class
protected java.lang.String	mCredentials Client credentials
protected JDBCConnectionProvider	mDataResource Database connection manager
protected java.lang.String	mExpression SQL expression
protected java.util.Set	mInputStreamNames Activity input names
protected BlockWriter	mOutput Activity output
protected SQLStatement	mStatement SQLStatement object for executing the SQL expression
static java.lang.String	RESULT_STREAM
static java.lang.String	SQL_OUT_PARAMETERS
static java.lang.String	SQL_PARAMETERS
static java.lang.String	STORED_PROCEDURE
static java.lang.String	WEB_ROW_SET_STREAM

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

mContext, mExternalInputs, mExternalOutputs, mInternalInputs, mInternalOutputs

Constructor Summary

AbstractSQLActivity(org.w3c.dom.Element element)

Method Summary

protected Pipe	createOutputPipe(int i) Creates an output pipe for an internal output.
void	initialise() This method should be overridden by subclasses to perform any initialisation they require before the process method invocations begin.
protected void	parseExpression(java.lang.String eltName, org.w3c.dom.NodeList list) Finds the SQL expression for this activity from the activity request XML.
protected void	parseResultStream(java.lang.String eltName, org.w3c.dom.NodeList list) Get the name of an output stream for the activity.

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

cleanUp, connectsTo, getActivityConfiguration, getActivityName, getCause, getName, getObservableStatus, getProperties, getSession, getStatus, hasActivityConfiguration, hasProperties, process, processBlock, 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

Copyright statement

See Also:

Constant Field Values

LOG

private static DAILogger LOG

Logger object for logging in this class

mCredentials

protected java.lang.String mCredentials

Client credentials

mDataResource

protected JDBCConnectionProvider mDataResource

Database connection manager

mOutput

protected BlockWriter mOutput

Activity output

mInputStreamNames

protected java.util.Set mInputStreamNames

Activity input names

mExpression

protected java.lang.String mExpression

SQL expression

mStatement

protected SQLStatement mStatement

SQLStatement object for executing the SQL expression

EXPRESSION

public static final java.lang.String EXPRESSION

Constants for parsing SQL activity XML

See Also:

Constant Field Values

STORED_PROCEDURE

public static final java.lang.String STORED_PROCEDURE

See Also:

Constant Field Values

CREATE_DATABASE

public static final java.lang.String CREATE_DATABASE

See Also:

Constant Field Values

DROP_DATABASE

public static final java.lang.String DROP_DATABASE

See Also:

Constant Field Values

SQL_PARAMETERS

public static final java.lang.String SQL_PARAMETERS

See Also:

Constant Field Values

SQL_OUT_PARAMETERS

public static final java.lang.String SQL_OUT_PARAMETERS

See Also:

Constant Field Values

WEB_ROW_SET_STREAM

public static final java.lang.String WEB_ROW_SET_STREAM

See Also:

Constant Field Values

RESULT_STREAM

public static final java.lang.String RESULT_STREAM

See Also:

Constant Field Values

Constructor Detail

AbstractSQLActivity

public AbstractSQLActivity(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.

parseExpression

protected void parseExpression(java.lang.String eltName,
                               org.w3c.dom.NodeList list)
                        throws ActivitySpecificationException

Finds the SQL expression for this activity from the activity request XML.

Parameters:

eltName - Name of element containing the expression.

list - A list of DOM nodes with tag eltName

Throws:

ActivitySpecificationException - If the first item in list does not contain an SQL expressions.

parseResultStream

protected void parseResultStream(java.lang.String eltName,
                                 org.w3c.dom.NodeList list)
                          throws ActivitySpecificationException

Get the name of an output stream for the activity.

Parameters:

eltName - Name of element containing the output stream name.

list - A list of DOM nodes with tag eltName and assumed to have attribute name with a non-null content.

Throws:

ActivitySpecificationException - If the first item in list does not contain an attribute name with a non-null value.

createOutputPipe

protected Pipe createOutputPipe(int i)

Description copied from class: Activity

Creates an output pipe for an internal output. This method can be overriden by subclasses in order to create specific types of output pipes.

Overrides:

createOutputPipe in class Activity

Parameters:

i - Index of the output pipe.

Returns:

an output pipe of suitable type.