java - lambda, netbeans, Error: incompatible Types error -

java - lambda, netbeans, Error: incompatible Types error -

i'm checking simple lambda expressions , have found in net next example, supposed work.

unfortunatelly, seems netbeans 8.0.1 not code in line (person p) -> p.getage() < 18) , .map((person p) -> p.getname())

the error "incompatible parameter types in lambda expression" shown.

anybody has thought how can right problem?

public class lambda { private enum gender { male, female }; public static class person { private final string name; private final int age; private final gender gender; public person(string name, int age, gender gender) { this.name = name; this.age = age; this.gender = gender; } public string getname() { homecoming name; } public int getage() { homecoming age; } public gender getgender() { homecoming gender; } } public static void main(string[] args) { list<person> persons = new arraylist<>(); persons.add(new person("angelo", 50, lambda.gender.male)); persons.add(new person("paolo", 10, lambda.gender.male)); persons.add(new person("giuseppe", 5, lambda.gender.male)); persons.add(new person("andrea", 22, lambda.gender.female)); persons.add(new person("guglielmo", 2, lambda.gender.female)); printnames(persons, (person p) -> p.getage() < 18); } private static void printnames(list<person> persons, predicate predicate) { persons.stream() .filter(predicate) .map((person p) -> p.getname()) .sorted() .foreach(name -> system.out.println(name)); } }

i suggest alter signature of method :

private static void printnames(list<person> persons, predicate predicate)

to

private static void printnames(list<person> persons, predicate<person> predicate)

your stream<person> created within method expects predicate<person> filter method.

java netbeans lambda java-8