Module dk.cloudcreate.essentials.components.foundation

Package dk.cloudcreate.essentials.components.foundation.postgresql

Class NotificationFilterChain

java.lang.Object

dk.cloudcreate.essentials.components.foundation.postgresql.NotificationFilterChain

public class NotificationFilterChain
extends Object

Manages a chain of NotificationDuplicationFilter instances and uses them to extract unique keys from the Notification.getParameter() JSON content.
The key extracted from NotificationDuplicationFilter.extractDuplicationKey(JsonNode) will be used inside MultiTableChangeListener for duplication checks across all Notification's returned in one poll.
If an empty Optional is returned then the given notification won't be deduplicated.
If two or more Notification's in a given poll batch share the same duplication key, then only one of them will be published to the listeners registered with the MultiTableChangeListener

Constructor Summary

Constructors

Constructor	Description
NotificationFilterChain(com.fasterxml.jackson.databind.ObjectMapper objectMapper)

Method Summary

Modifier and Type	Method	Description
boolean	addFilterAsFirst(NotificationDuplicationFilter filter)	Adds a custom NotificationDuplicationFilter to the filter chain as the very first (highest priority). Note: Only a single instance of a particular NotificationDuplicationFilter, determined by calling Object.equals(Object) on the filters, can be added
boolean	addFilterAsLast(NotificationDuplicationFilter filter)	Adds a custom NotificationDuplicationFilter to the filter chain as the very last (lowest priority). Note: Only a single instance of a particular NotificationDuplicationFilter, determined by calling Object.equals(Object) on the filters, can be added
Optional<String>	extractDuplicationKey(String parameterJson)	Extracts the duplication key from the given JSON parameter string using the registered NotificationDuplicationFilter's in sequence.
boolean	hasDuplicationFilters()	Are there any NotificationDuplicationFilter added to the chain?
void	removeFilter(NotificationDuplicationFilter filter)	Removes a custom NotificationDuplicationFilter from the filter chain.

Methods inherited from class java.lang.Object

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

Constructor Details

NotificationFilterChain

public NotificationFilterChain(com.fasterxml.jackson.databind.ObjectMapper objectMapper)

Method Details

addFilterAsFirst

public boolean addFilterAsFirst(NotificationDuplicationFilter filter)

Adds a custom NotificationDuplicationFilter to the filter chain as the very first (highest priority).
Note: Only a single instance of a particular NotificationDuplicationFilter, determined by calling Object.equals(Object) on the filters, can be added

Parameters:

filter - the filter to be added to the chain

Returns:

true if the filter was added as the first, otherwise false (e.g. the filter was already added)

addFilterAsLast

public boolean addFilterAsLast(NotificationDuplicationFilter filter)

Adds a custom NotificationDuplicationFilter to the filter chain as the very last (lowest priority).
Note: Only a single instance of a particular NotificationDuplicationFilter, determined by calling Object.equals(Object) on the filters, can be added

Parameters:

filter - the filter to be added to the chain

Returns:

true if the filter was added as the last, otherwise false (e.g. the filter was already added)

removeFilter

public void removeFilter(NotificationDuplicationFilter filter)

Removes a custom NotificationDuplicationFilter from the filter chain.

Parameters:

filter - the filter to be added to the chain

extractDuplicationKey

public Optional<String> extractDuplicationKey(String parameterJson)

Extracts the duplication key from the given JSON parameter string using the registered NotificationDuplicationFilter's in sequence. The first NotificationDuplicationFilter to return a non-empty Optional determines the key.
If an empty Optional is returned then the given notification won't be deduplicated.

Parameters:

parameterJson - the JSON string representation of the Notification.getParameter() JSON content.

Returns:

an Optional containing the unique key if extraction was successful, otherwise an empty Optional.

Throws:

IllegalArgumentException - if the JSON is invalid or no unique key can be extracted

hasDuplicationFilters

public boolean hasDuplicationFilters()

Are there any NotificationDuplicationFilter added to the chain?

Returns:

if there are any NotificationDuplicationFilter added to the chain?