<dependency>
  <groupId>de.scravy</groupId>
  <artifactId>primes4j</artifactId>
  <version>2</version>
</dependency>

import de.scravy.primes.Primes;

public class Example1 {
  public static void main(final String[] args) {
    final Primes primes = Primes.load(10000); // only loads 10000 primes which is faster
    System.out.println(primes.getPrimeFactors(2868)); // prints [2, 2, 3, 239]
  }
}

import de.scravy.primes.Primes;

public class Example {
  public static void main(final String[] args) {
    final Primes primes = Primes.load(); // takes a while as it loads all primes into memory
    System.out.println(primes.isPrime(Integer.MAX_VALUE)); // prints true
  }
}