Fava - advanced functional Java

JDK 11+

Using Java Profile

Java Lambda: Method Reference

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Type	Syntax	Lambda
Reference to a static method	ClassName::staticMethodName	(args) -> ClassName.staticMethodName(args)
Reference to an instance method of an existing object	object::instanceMethodName	(args) -> object.instanceMethodName(args)
Reference to an instance method of an arbitrary object of a particular type	ClassName::instanceMethodName	(arg0,rest) -> arg0.instanceMethodName(rest) Note: argo is of type ClassName
Reference to a constructor	ClassName::new	(args) -> new ClassName(args)

Lambda Examples

@FunctionalInterface
public interface IF2<T1, T2, R> {
	R apply(T1 t1, T2 t2);
}

means two input parameters and one output parameter

(a, b) -> a.split(b)1 equals IF2<String, String, String[]> if2 = String::split

Other

• vavr handy functional library
• java-promise
• versy useful Future vs Promise summarise
• jOOλ

Test with Spock

• Spock Document
• Spock Examples
• Groovy List
• Book: Making Java Groovy

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• https://dzone.com/articles/java-lambda-method-reference
• https://www.baeldung.com/java-method-references