FunctionalInterfaceLogic

java.lang.Object

com.github.javaparser.resolution.logic.FunctionalInterfaceLogic

public final class FunctionalInterfaceLogic extends Object

Author:: Federico Tomassetti

Method Summary

Modifier and Type

Method

Description

static Optional<MethodUsage>

getFunctionalMethod(ResolvedReferenceTypeDeclaration typeDeclaration)

Get the functional method defined by the type, if any.

static Optional<MethodUsage>

getFunctionalMethod(ResolvedType type)

Get the functional method defined by the type, if any.

static boolean

isFunctionalInterfaceType(ResolvedType type)

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details
- getFunctionalMethod
  public static Optional<MethodUsage> getFunctionalMethod(ResolvedType type)
  
  Get the functional method defined by the type, if any.
  Per JLS §9.8, a functional interface is always an interface, which is a reference type. Primitive types, array types, and void can therefore never be functional interfaces. Passing such a type returns Optional.empty() immediately without throwing an exception.
  Note: bounded type variables (<T extends Runnable>) and intersection types (Runnable & Serializable) are not handled here and also return Optional.empty(). Supporting those cases is a separate, more complex enhancement (see JLS §15.27.3).
  
  Parameters:
  
  type - the resolved type to inspect — may be any ResolvedType subclass
  
  Returns:
  
  the single abstract method of the functional interface, or empty if the type is not a functional interface or is not a reference type at all
  
  See Also:
  
  Issue #3625
- getFunctionalMethod
  
  public static Optional<MethodUsage> getFunctionalMethod(ResolvedReferenceTypeDeclaration typeDeclaration)
  
  Get the functional method defined by the type, if any.
- isFunctionalInterfaceType
  
  public static boolean isFunctionalInterfaceType(ResolvedType type)