1 /* 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 import java.util.Arrays; 25 import java.util.SystemRandom; 26 27 /* 28 * @test 29 * @summary Test for java.util.SystemRandom 30 */ 31 public class SystemRandomTest { 32 public static void main(String[] args) { 33 System.out.println("SystemRandomTest... (8 bytes / invocation)"); 34 byte[] bytes = new byte[8]; 35 long t0 = System.nanoTime(); 36 try (SystemRandom sr = SystemRandom.newInstance()) { 37 sr.getBytes(bytes); 38 long t1 = System.nanoTime(); 39 System.out.println("1st invocation: " + 40 (t1 - t0) + " ns, result: " + Arrays.toString(bytes)); 41 42 final int N = 1_000_000; 43 44 t0 = System.nanoTime(); 45 for (int i = 0; i < N; i++) { 46 sr.getBytes(bytes); 47 } 48 t1 = System.nanoTime(); 49 50 System.out.println("Following " + N + " invocations: " + 51 ((double)(t1 - t0)/1e9d) + " s, (" + 52 ((t1-t0)/N) + " ns/invocation)"); 53 } 54 } 55 }