equinox-backend/com.tecknobit.equinoxbackend.environment.helpers/FilteredQuery

Filtered Query

abstract class FilteredQuery<T>

The FilteredQuery<T> class is an abstract helper designed to facilitate the dynamic creation and execution of filtered queries using JPA Criteria API. It is structured to simplify filtering, querying, and pagination of entities from a database while allowing custom predicates to be added dynamically by subclasses

Author

Tecknobit - N7ghtm4r3

Since

1.0.5

Parameters

<T>

Type of the entities to retrieve

Constructors

constructor(entityType: Class<T>, entityManager: EntityManager, rawFilters: Set<String>)

Constructor to init the FilteredQuery

Properties

criteriaBuilder

protected val criteriaBuilder: CriteriaBuilder

criteriaBuilder the builder to add the criteria to filter the query

protected val entityManager: EntityManager

entityManager manage the entities

protected val predicates: ArrayList<Predicate>

predicates the list of predicates to apply to the query

protected val query: CriteriaQuery<T>

query the criteria prepared query to execute

protected val rawFilters: CopyOnWriteArraySet<String>

rawFilters the filters all together in raw format

protected val root: Root<T>

root the root table

Functions

extractFiltersByPattern

protected open fun extractFiltersByPattern(pattern: Pattern): HashSet<String>

Method to extract from the rawFilters the specific set of filters

protected abstract fun fillPredicates()

Wrapper method to fill all the predicates dynamically

open fun getEntities(): List<T>

Method to get the entities executing the query

open fun getEntities(pageable: Pageable): List<T>

Method to get the paginated entities executing the query

private open fun prepareQuery()

Method to prepare the query adding the predicates