What am I doing wrong with java 8 lambda Predicate <Integer>?

Question

This is not a duplicate of my question. I checked it, and mine - use the correct Predicate, and THAT - about the differences between removeIf and removal.

I am starting a Java programmer.
Yesterday I tried to follow this tutorial https://dzone.com/articles/why-we-need-lambda-expressions
After I got rid of using lambda expressions and Predicate, I made my own code for practice.
for example, sum all numbers if (n% 3 == 0 || n% 5 == 0). here is my code.

public class Euler1Lambda {
    long max;
    public Euler1Lambda(long max) {
        this.max = max;
    }
public static boolean div3remainder0(int number) {
    return number % 3 == 0;
}

public static boolean div5remainder0(int number) {
    return number % 5 == 0;
}

public long sumAll() {
    long sum = 0;
    for(int i=1; i<max; i++) {
        if (div3remainder0(i) ||div5remainder0(i)) {
            sum += i;
        }
    }
    return sum;
}

public long sumAllLambda(Predicate<Integer> p) {
    long total = 0;
    for (int i = 1; i< max; i++){
        if (p.test(i)) {
            total += i;
        }
    }
return total;
}

public static void main(String[] args) {
    //conv
    long startTime = System.currentTimeMillis();
    for(int i = 0; i < 10; i++){
        new Euler1Lambda(100000000).sumAll();
    }
    long endTime = System.currentTimeMillis();
    long conv = (endTime - startTime);
    System.out.println("Total execution time: " + conv);
    //lambda
    startTime = System.currentTimeMillis();
    for(int i = 0; i < 10; i++){
        new Euler1Lambda(100000000).sumAllLambda(n -> div3remainder0(n) || div5remainder0(n));
    }
    endTime = System.currentTimeMillis();
    long lambda = (endTime - startTime);
    System.out.println("Total execution time: " + lambda);
    System.out.println("lambda / conv : " + (float)lambda/conv);
}
}

This code performed temporary tests. and the result is this.

Total execution time conv: 1761
Total execution time lambda: 3266

lambda / conv : 1.8546281

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, .
? ?

Answer 1

, . 1505 100000000 15 . .

, int Integers Predicate<Integer>. Predicate::test Integer, p.test(i) p.test(Integer.valueOf(i)). , . -, 15 .

IntPredicate, int , , - , - .

, Java ( , , ​​ JMH ..). , , , .

Answer 2

. Integer .

public long sumAllLambda(Predicate<Integer> p) 

public long sumAllLambda(IntPredicate p) 

Total execution time conv: 3190
Total execution time lambda: 3037
lambda / conv : 0.95203763