Package com.denodo.vdb.engine.customwrapper

Class AbstractCustomWrapper

java.lang.Object

com.denodo.vdb.engine.customwrapper.AbstractCustomWrapper

All Implemented Interfaces:

CustomWrapper

public abstract class AbstractCustomWrapper
extends Object
implements CustomWrapper

Default implementation of CustomWrapper. Subclasses need only to implement the methods CustomWrapper.getSchemaParameters(java.util.Map<java.lang.String, java.lang.String>) and CustomWrapper.run(com.denodo.vdb.engine.customwrapper.condition.CustomWrapperConditionHolder, java.util.List<com.denodo.vdb.engine.customwrapper.expression.CustomWrapperFieldExpression>, com.denodo.vdb.engine.customwrapper.CustomWrapperResult, java.util.Map<java.lang.String, java.lang.String>), as default implementations for the rest of the required methods are provided.

Nevertheless, the user is encouraged to override any of the methods provided by this class if necessary.

Field Summary

Fields

Modifier and Type	Field	Description
protected static final int	LOG_DEBUG	'Debug' log level
protected static final int	LOG_ERROR	'Error' log level
protected static final int	LOG_FATAL	'Fatal' log level
protected static final int	LOG_INFO	'Info' log level
protected static final int	LOG_TRACE	'Trace' log level
protected static final int	LOG_WARN	'Warn' log level

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractCustomWrapper()

Method Summary

Modifier and Type	Method	Description
void	commit()	By default, does nothing.
int	delete(CustomWrapperConditionHolder condition, Map<String,String> inputValues)	By default, does nothing and returns 0.
CustomWrapperConfiguration	getConfiguration()	By default, returns a CustomWrapperConfiguration instance with all the configuration parameters set to their default values.
CustomWrapperPlan	getCustomWrapperPlan()	Returns the CustomWrapperPlan of the current wrapper execution.
CustomWrapperInputParameter[]	getDataSourceInputParameters()	By default, an empty array is returned.
CustomWrapperInputParameter[]	getInputParameters()	By default, an empty array is returned.
protected final CustomWrapperInputParameterValue	getInputParameterValue(String name)	Returns the actual CustomWrapperInputParameterValue associated to the CustomWrapperInputParameter specified by the name.
protected final List<CustomWrapperOrderByExpression>	getOrderByExpressions()	If the Custom Wrapper declares in the CustomWrapperConfiguration that it supports orderBy delegations, it returns a List with the expressions in the ORDER BY clause delegated to the custom wrapper.
CustomWrapperSchemaParameter[]	getSchema()	Returns the schema of this wrapper.
int	insert(Map<CustomWrapperFieldExpression,Object> insertValues, Map<String,String> inputValues)	By default, does nothing and returns 0.
protected final void	log(int level, String logMessage)	Adds an entry log, with the specified level.
void	prepare()	By default, does nothing.
void	rollback()	By default, does nothing.
final void	setInputParameterValues(Map<String,CustomWrapperInputParameterValue> paramValues)	Sets the input parameter values with type information.
final void	setOrderByExpressions(List<CustomWrapperOrderByExpression> orderByExpressions)	Sets the order by expressions when they are delegated to the source
void	setSchema(CustomWrapperSchemaParameter[] customWrapperSchema)	Important: do not invoke this method.
boolean	stop()	By default, does nothing and returns false.
int	update(Map<CustomWrapperFieldExpression,Object> updateValues, CustomWrapperConditionHolder condition, Map<String,String> inputValues)	By default, does nothing and returns 0.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.denodo.vdb.engine.customwrapper.CustomWrapper

getSchemaParameters, run

Field Details

LOG_TRACE

protected static final int LOG_TRACE

'Trace' log level

See Also:

• Constant Field Values

LOG_DEBUG

protected static final int LOG_DEBUG

'Debug' log level

See Also:

• Constant Field Values

LOG_INFO

protected static final int LOG_INFO

'Info' log level

See Also:

• Constant Field Values

LOG_WARN

protected static final int LOG_WARN

'Warn' log level

See Also:

• Constant Field Values

LOG_ERROR

protected static final int LOG_ERROR

'Error' log level

See Also:

• Constant Field Values

LOG_FATAL

protected static final int LOG_FATAL

'Fatal' log level

See Also:

• Constant Field Values

Constructor Details

AbstractCustomWrapper

protected AbstractCustomWrapper()

Method Details

getDataSourceInputParameters

public CustomWrapperInputParameter[] getDataSourceInputParameters()

By default, an empty array is returned.

Specified by:

getDataSourceInputParameters in interface CustomWrapper

Returns:

an array of CustomWrapperInputParameter

See Also:

• CustomWrapperInputParameter

getInputParameters

public CustomWrapperInputParameter[] getInputParameters()

By default, an empty array is returned.

Specified by:

getInputParameters in interface CustomWrapper

Returns:

an array of CustomWrapperInputParameter

See Also:

• CustomWrapperInputParameter

insert

public int insert(Map<CustomWrapperFieldExpression,Object> insertValues,
 Map<String,String> inputValues)
           throws CustomWrapperException

By default, does nothing and returns 0.

Specified by:

insert in interface CustomWrapper

Parameters:

insertValues - a Map<CustomWrapperFieldExpression, Object> which associates fields with values, in similar fashion to the INSERT statement in SQL.

inputValues - a Map<String, String> which associates this Custom Wrapper's input parameters' names (as defined in CustomWrapper.getInputParameters()) with their current values.

Returns:

the number of successfully inserted values.

Throws:

CustomWrapperException - Throw this exception from your code if there is an error inserting a row in the underlying data source. The execution engine will capture this exception and will interrupt the execution of this custom wrapper, interrupt the query and return the error message of this exception to the client application.

See Also:

• CustomWrapperFieldExpression

delete

public int delete(CustomWrapperConditionHolder condition,
 Map<String,String> inputValues)
           throws CustomWrapperException

By default, does nothing and returns 0.

Specified by:

delete in interface CustomWrapper

Parameters:

condition - the deletion condition (akin to the WHERE clause in a SQL DELETE statement).

inputValues - a Map<String, String> which associates this Custom Wrapper's input parameters' names (as defined in CustomWrapper.getInputParameters()) with their current values.

Returns:

the number of successfully deleted values.

Throws:

CustomWrapperException - Throw this exception from your code if there is an error deleting a row in the underlying data source. The execution engine will capture this exception and will interrupt the execution of this custom wrapper, interrupt the query and return the error message of this exception to the client application.

See Also:

• CustomWrapperConditionHolder

update

public int update(Map<CustomWrapperFieldExpression,Object> updateValues,
 CustomWrapperConditionHolder condition,
 Map<String,String> inputValues)
           throws CustomWrapperException

By default, does nothing and returns 0.

Specified by:

update in interface CustomWrapper

Parameters:

updateValues - a Map<CustomWrapperFieldExpression, Object> which associates fields with values, in similar fashion to the UPDATE statement in SQL. The value can be a literal expressed as a Java object or a field expressed as a CustomWrapperFieldExpression

condition - the insert condition (akin to the WHERE clause in a SQL UPDATE statement).

inputValues - a Map<String, String> which associates this Custom Wrapper's input parameters' names (as defined in CustomWrapper.getInputParameters()) with their current values.

Returns:

the number of successfully updated values.

Throws:

CustomWrapperException - Throw this exception if there is an error updating a row in the underlying data source. The execution engine will capture this exception and will interrupt the execution of this custom wrapper, interrupt the query and return the error message of this exception to the client application.

See Also:

• CustomWrapperFieldExpression
• CustomWrapperConditionHolder

commit

public void commit()

By default, does nothing.

Specified by:

commit in interface CustomWrapper

rollback

public void rollback()

By default, does nothing.

Specified by:

rollback in interface CustomWrapper

prepare

public void prepare()

By default, does nothing.

Specified by:

prepare in interface CustomWrapper

stop

public boolean stop()

By default, does nothing and returns false.

Specified by:

stop in interface CustomWrapper

Returns:

true if this Custom Wrapper can stop its execution, false otherwise.

getConfiguration

public CustomWrapperConfiguration getConfiguration()

By default, returns a CustomWrapperConfiguration instance with all the configuration parameters set to their default values.

Specified by:

getConfiguration in interface CustomWrapper

Returns:

a CustomWrapperConfiguration instance defining this Custom Wrapper configuration parameters.

setInputParameterValues

public final void setInputParameterValues(Map<String,CustomWrapperInputParameterValue> paramValues)

Sets the input parameter values with type information.

Parameters:

paramValues - input parameter values to be set

getInputParameterValue

protected final CustomWrapperInputParameterValue getInputParameterValue(String name)

Returns the actual CustomWrapperInputParameterValue associated to the CustomWrapperInputParameter specified by the name.

Parameters:

name - the name of the CustomWrapperInputParameter whose CustomWrapperInputParameterValue is returned.

Returns:

the actual CustomWrapperInputParameterValue associated to the CustomWrapperInputParameter specified by the name.

setOrderByExpressions

public final void setOrderByExpressions(List<CustomWrapperOrderByExpression> orderByExpressions)

Sets the order by expressions when they are delegated to the source

Parameters:

orderByExpressions - order by expressions to be set

getOrderByExpressions

protected final List<CustomWrapperOrderByExpression> getOrderByExpressions()

If the Custom Wrapper declares in the CustomWrapperConfiguration that it supports orderBy delegations, it returns a List with the expressions in the ORDER BY clause delegated to the custom wrapper.

Returns:

a List with the expressions in the ORDER BY clause delegated to the custom wrapper.

log

protected final void log(int level,
 String logMessage)

Adds an entry log, with the specified level.

Parameters:

level - the desired log level. Should be one of these:

• LOG_TRACE
• LOG_DEBUG
• LOG_INFO
• LOG_WARN
• LOG_ERROR
• LOG_FATAL

logMessage - the message to be logged.

getCustomWrapperPlan

public CustomWrapperPlan getCustomWrapperPlan()

Returns the CustomWrapperPlan of the current wrapper execution.

Returns:

the CustomWrapperPlan of the current wrapper execution.

getSchema

public CustomWrapperSchemaParameter[] getSchema()

Returns the schema of this wrapper. This method returns null if invoked from the constructor of the custom wrapper. It has to invoked once the class has been instanced.

Returns:

array of CustomWrapperSchemaParameter objects that represent the schema of this wrapper.

Since:

7.0u20200310

setSchema

public void setSchema(CustomWrapperSchemaParameter[] customWrapperSchema)

Important: do not invoke this method. For internal purposes only.

Parameters:

customWrapperSchema - -

Since:

7.0u20200310