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https://issues.apache.org/jira/browse/LANG-823?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18048551#comment-18048551
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Abhineet Kelley commented on LANG-823:
--------------------------------------
Hi [~ggregory]
Sharing the same view as the comment by [~chonton], for curiosity may I please
know why have we kept a different behaviour for {{*StringUtils.split*}} from
the native {{*String.split*}} method in case of empty strings?
{noformat}
StringUtils.split("", *) -> []
"".split(*) -> [""]{noformat}
Actually, there was a recent instance wherein to reduce the cognitive
complexity of our production code, I had used *{{StringUtils.split}}* to handle
null strings internally. However when our unit tests failed I observed that it
behaves differently from native Java in case of empty strings. Therefore I had
to switch to the native implementation to handle this case.
This was basically our previous code:
{noformat}
// -- continues --
String phoneNumbers = dto.getPhoneNumbers();
newDTO.setPhoneNumber("");
if (phoneNumbers != null) {
newDTO.setPhoneNumber(phoneNumbers.split(",")[0]);
}
// -- continues --{noformat}
This is what I was hoping to do with *StringUtils* (commons-lang3 : 3.20.0)
after the refactor:
{code:java}
String phoneNumbers = StringUtils.defaultIfBlank(dto.getPhoneNumbers(),
StringUtils.EMPTY);
newDTO.setPhoneNumber(StringUtils.split(phoneNumbers, ",")[0]);{code}
But I eventually went with the one below because at this point, the variable
{{*phoneNumbers*}} wouldn't be null anymore. Thus using StringUtils for
splitting the string would be optional.
{code:java}
String phoneNumbers = StringUtils.defaultIfBlank(dto.getPhoneNumbers(),
StringUtils.EMPTY);
newDTO.setPhoneNumber(phoneNumbers.split(",")[0]);{code}
This did however made me curious about the implementation we have in
commons-lang3.
> StringUtils.split should handle empty strings the same as other content
> -----------------------------------------------------------------------
>
> Key: LANG-823
> URL: https://issues.apache.org/jira/browse/LANG-823
> Project: Commons Lang
> Issue Type: Improvement
> Components: lang.*
> Affects Versions: 2.5
> Reporter: Mark Farnsworth
> Assignee: Benedikt Ritter
> Priority: Minor
> Fix For: Review Patch, Discussion, 3.x
>
> Attachments: LANG-823.patch, LANG-823.test.patch
>
>
> When a user issues a split with a delimiter and the string does not contain
> the delimiter the result is normally an array with one item that contains the
> content of the string.
> It seems strange that StringUtils does not behave consistently in the context
> of an empty string.
> For example,
> {code}
> package maf.test;
> import junit.framework.TestCase;
> import org.apache.commons.lang.StringUtils;
> public class StringUtilsTest extends TestCase {
> public void testStringUtils() {
> // The following two lines work correctly
> assertTrue(StringUtils.split("x",",")[0].equals("x"));
> assertTrue(StringUtils.split(" ",",")[0].equals(" "));
>
> // The following should also work but
> // in commons-lang-2.5.jar the test fails here
> assertTrue(StringUtils.split("",",")[0].equals(""));
> }
> }
> {code}
> There seems to be no logic behind making split work differently in the case
> of empty strings.
> For the next release, I would suggest a behavior change for StringUtils this
> will have side effects but would be more logically consistent.
> Users who depend on the old behavior could stick with 2.5 release and/or
> implement code in the caller to simulate the behavior.
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