import java.util.function.Function;

/*Opcion 1*/
Function square = 
new Function() {
            
    @Override
    public Integer apply(Integer x) {
        return x*x;
    }
};

/*Opcion 2*/
Function square = x -> x*x;

import java.util.function.Predicate;

/*Ejemplo*/
Predicate< Student > isApproved = student -> student.getCalificacion() > 6.0;

Student bexperr = new Student(7.0);
isApproved.test(bexperr);

/*Objeto*/
static class Student {
    private double calificacion;

    public Student(double calificacion){
        this.calificacion =calificacion;
    }

    public double getCalificacion() {
        return calificacion;
    }
}