ParalleleStream

Test Simple

public class SimpleParallele {

	    public static void main(String[] args) {

	        System.out.println("Normal...");
	      
			IntStream range = IntStream.rangeClosed(1, 10);
	        range.forEach(System.out::println);

	        System.out.println("Parallel...");

	        IntStream range2 = IntStream.rangeClosed(1, 10);
	        range2.parallel().forEach(System.out::println);

	    }

	
}

 

Résultat

Normal...
1
2
3
4
5
6
7
8
9
10
Parallel...
7
6
8
1
2
4
10
3
9
5

 

Test 2 Test des nombres premiers

  public static void main(String[] args) {

    	long now=System.currentTimeMillis();
    	
        long count = Stream.iterate(0, n -> n + 1)
                .limit(1_00000)
                .filter(Prime::isPrime)
                .peek(x -> System.out.format("%s\t", x))
                .count();

        System.out.println("\nTotal: " + count);
        System.err.println("Time :" + (System.currentTimeMillis()-now));

	 now=System.currentTimeMillis();
    	
         count = Stream.iterate(0, n -> n + 1)
                .limit(1_00000)
                .parallel() 
                .filter(Prime::isPrime)
                .peek(x -> System.out.format("%s\t", x))
                .count();

        System.out.println("\nTotal: " + count);
        System.err.println("Time :" + (System.currentTimeMillis()-now));
    }

    public static boolean isPrime(int number) {
        if (number <= 1) return false;
        return !IntStream.rangeClosed(2, number / 2).anyMatch(i -> number % i == 0);
    }

Résultat

Total: 9592
Time :1455

Total: 9592
Time :392