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https://issues.apache.org/jira/browse/LANG-1592?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17161822#comment-17161822
]
Alex Herbert commented on LANG-1592:
------------------------------------
This occurs as the method is using the {{nextDouble(double min, double max)}}
method then casting back to a {{long}}.
A correct implementation would be to work only with the {{long}} datatype:
{code:java}
public static long nextLong(final long startInclusive, final long endExclusive)
{
Validate.isTrue(endExclusive >= startInclusive,
"Start value must be smaller or equal to end value.");
Validate.isTrue(startInclusive >= 0, "Both range values must be
non-negative.");
if (startInclusive == endExclusive) {
return startInclusive;
}
return startInclusive + nextLong(endExclusive - startInclusive);
}
/**
* Create a random long in the range 0 inclusive to {@code n} exclusive.
*
* @param n the upper limit (exclusive)
* @return the long
*/
private static long nextLong(long n) {
long bits;
long val;
do {
bits = RANDOM.nextLong() >>> 1;
val = bits % n;
} while (bits - val + (n - 1) < 0);
return val;
}
{code}
> The random number generated by RandomUtils exceeds the exclusive parameter
> --------------------------------------------------------------------------
>
> Key: LANG-1592
> URL: https://issues.apache.org/jira/browse/LANG-1592
> Project: Commons Lang
> Issue Type: Bug
> Components: lang.*
> Affects Versions: 3.11
> Reporter: huang pingcai
> Priority: Minor
> Attachments: image-2020-07-21-14-35-27-870.png
>
>
> {code:java}
> @Test
> public void test() {
> while (RandomUtils.nextLong(12900000000001L, 12900000000016L) !=
> 12900000000016L) {
> }
> System.out.println("should not be invoked");
> }
> {code}
> !image-2020-07-21-14-35-27-870.png|width=315,height=182!
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