FunctionalInterfaceLogic

java.lang.Object
- com.github.javaparser.resolution.logic.FunctionalInterfaceLogic

public final class FunctionalInterfaceLogic
extends java.lang.Object

Author:: Federico Tomassetti

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static java.util.Optional<MethodUsage>`	`getFunctionalMethod(ResolvedReferenceTypeDeclaration typeDeclaration)`	Get the functional method defined by the type, if any.
`static java.util.Optional<MethodUsage>`	`getFunctionalMethod(ResolvedType type)`	Get the functional method defined by the type, if any.
`static boolean`	`isFunctionalInterfaceType(ResolvedType type)`

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

- Method Detail
  - getFunctionalMethod
```
public static java.util.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 java.util.Optional<MethodUsage> getFunctionalMethod(ResolvedReferenceTypeDeclaration typeDeclaration)
```
    Get the functional method defined by the type, if any.
  - isFunctionalInterfaceType
```
public static boolean isFunctionalInterfaceType(ResolvedType type)
```