Package in.co.akshitbansal.springwebquery.util

Class PreferredConstructorDiscoveryUtil

java.lang.Object
in.co.akshitbansal.springwebquery.util.PreferredConstructorDiscoveryUtil
public class PreferredConstructorDiscoveryUtil extends Object
Discovers the constructor that should be used to convert a projected JPA Tuple into a DTO instance.

Compatibility is determined by constructor parameter order, parameter count, and runtime type assignability for each tuple element. Primitive constructor parameter types are normalized to their wrapper types before compatibility checks are performed.

When multiple constructors are compatible, a constructor annotated with PersistenceCreator is preferred. Callers should keep at most one such annotated constructor. If multiple annotated constructors are present, or if multiple non-annotated constructors are compatible, constructor selection is not guaranteed to be stable and behavior is unpredictable.

  • Constructor Details

    • PreferredConstructorDiscoveryUtil

      public PreferredConstructorDiscoveryUtil()

  • Method Details

    • discover

      public static Constructor<?> discover(@NonNull @NonNull Class<?> clazz, @NonNull @NonNull jakarta.persistence.Tuple tuple)
      Finds a compatible constructor for the given tuple-backed DTO projection.

      The selected constructor must declare the same number of parameters as the tuple contains elements, and each parameter must be assignable from the corresponding tuple element runtime Java type after primitive-wrapper normalization. Compatible constructors are evaluated in declared-constructor order, with a compatible constructor annotated with PersistenceCreator taking precedence over any previously found compatible constructor.

      If no compatible constructor exists, this method throws an IllegalArgumentException. If multiple compatible constructors exist without a uniquely determining preference, the returned constructor depends on the current implementation details of discovery and should not be treated as stable API behavior.

      Parameters:
      clazz - target DTO type whose constructors should be inspected
      tuple - tuple whose projected element count and runtime types drive compatibility checks
      Returns:
      the compatible constructor selected for tuple-backed instantiation
      Throws:
      IllegalArgumentException - if no suitable constructor can be found