Created
October 30, 2015 15:44
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Infinite stream of prime numbers
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package com.example; | |
import java.io.IOException; | |
import java.util.List; | |
import java.util.stream.Collectors; | |
import java.util.stream.IntStream; | |
import java.util.stream.Stream; | |
public class MessingAround { | |
public static void main(String[] args) throws IOException, InterruptedException { | |
System.out.println(primes(10,10)); | |
} | |
public static List<Integer> primes(final int fromNumber, final int count) { | |
return Stream.iterate(primeAfter(fromNumber - 1), MessingAround::primeAfter) | |
.limit(count).collect(Collectors.<Integer>toList()); | |
} | |
private static int primeAfter(final int number) { | |
if (isPrime(number + 1)) return number + 1; | |
else | |
return primeAfter(number + 1); | |
} | |
public static boolean isPrime(final int number) { | |
return number > 1 && | |
IntStream.rangeClosed(2, (int) Math.sqrt(number)).noneMatch(divisor -> number % divisor == 0); | |
} | |
} |
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