com.neurosys.etl.common.transformers

Class LastStateLatchTransformer

java.lang.Object

com.neurosys.etl.common.transformers.LastStateLatchTransformer

All Implemented Interfaces:

FunctionTransformer, Serializable, Function, org.apache.commons.collections.Transformer

public class LastStateLatchTransformer
extends Object
implements FunctionTransformer, Serializable

If we have a List or Set of records that are delimited or separated by some logically identifiable variables then it is desireable to have a state-ful mechanism that can tell us what state does the current record belong in based on its delimited position.
Example:
+--------------------------------------------------------------+
| DELIM 1 | Rec1 | Rec2 | Rec3 | DELIM 2 | RecA | RecB | RecC |
+--------------------------------------------------------------+
.. while traversing the above list this Transformer will be able to indicate that Rec2 belongs under DELIM1 while RecC belongs under DELIM2.
If throwContinueOnStateChange is true it will trigger a state change event on DELIM1 & DELIM2.

For a Given List of values; if the input matches any the state of the instance will return that state as a result of the Transformation process
You may override the matching behavior by overriding {@link #matches(Object)

THIS IS A STATEFUL BEAN AND SHOULD NOT BE A SINGLETON

Author:

Arjun Dhar

See Also:

matcherValues, for use case where this can be applied, Serialized Form

Constructor Summary

Constructors

Constructor and Description
LastStateLatchTransformer()

Method Summary

Modifier and Type	Method and Description
Object	getLastState() The last state encountered
Collection	getMatcherValues() If any of the this matches the input (including null values) it will result in the state change to the latest matching value in matcherValues
boolean	isThrowContinueOnStateChange() If true, if the input triggers a State change (based on the result of matches(Object)); then throw a ContinueProcessingException Useful if we want to exclude the cause of the state change itself
protected boolean	matches(Object input)
void	setLastState(Object lastState) The last state encountered
void	setMatcherValues(Collection matcherValues) If any of the this matches the input (including null values) it will result in the state change to the latest matching value in matcherValues
void	setThrowContinueOnStateChange(boolean throwContinueOnStateChange) If true, if the input triggers a State change (based on the result of matches(Object)); then throw a ContinueProcessingException Useful if we want to exclude the cause of the state change itself
Object	transform(Object input)

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.neurosys.etl.common.transformers.FunctionTransformer

apply

Methods inherited from interface java.util.function.Function

andThen, compose, identity

Constructor Detail

LastStateLatchTransformer

public LastStateLatchTransformer()

Method Detail

matches

protected boolean matches(Object input)

transform

public Object transform(Object input)

Specified by:

transform in interface org.apache.commons.collections.Transformer

isThrowContinueOnStateChange

public boolean isThrowContinueOnStateChange()

If true, if the input triggers a State change (based on the result of matches(Object)); then throw a ContinueProcessingException
Useful if we want to exclude the cause of the state change itself

Default value:

false

setThrowContinueOnStateChange

public void setThrowContinueOnStateChange(boolean throwContinueOnStateChange)

If true, if the input triggers a State change (based on the result of matches(Object)); then throw a ContinueProcessingException
Useful if we want to exclude the cause of the state change itself

Default value:

false

getMatcherValues

public Collection getMatcherValues()

If any of the this matches the input (including null values) it will result in the state change to the latest matching value in matcherValues

setMatcherValues

public void setMatcherValues(Collection matcherValues)

If any of the this matches the input (including null values) it will result in the state change to the latest matching value in matcherValues

getLastState

public Object getLastState()

The last state encountered

setLastState

public void setLastState(Object lastState)

The last state encountered