1 /*

     2  * Copyright (c) 2017, 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 package java.net.http;

    25 

    26 import java.util.Random;

    27 

    28 /** Abstract supertype for tests that need random numbers within a given range. */

    29 public class AbstractRandomTest {

    30 

    31     private static Long getSystemSeed() {

    32         Long seed = null;

    33         try {

    34             // note that Long.valueOf(null) also throws a NumberFormatException

    35             // so if the property is undefined this will still work correctly

    36             seed = Long.valueOf(System.getProperty("seed"));

    37         } catch (NumberFormatException e) {

    38             // do nothing: seed is still null

    39         }

    40         return seed;

    41     }

    42 

    43     private static long getSeed() {

    44         Long seed = getSystemSeed();

    45         if (seed == null) {

    46             seed = (new Random()).nextLong();

    47         }

    48         System.out.println("Seed from AbstractRandomTest.getSeed = "+seed+"L");

    49         return seed;

    50     }

    51 

    52     private static Random random = new Random(getSeed());

    53 

    54     protected static int randomRange(int lower, int upper) {

    55         if (lower > upper)

    56             throw new IllegalArgumentException("lower > upper");

    57         int diff = upper - lower;

    58         int r = lower + random.nextInt(diff);

    59         return r - (r % 8); // round down to multiple of 8 (align for longs)

    60     }

    61 }