Simple regex working on Windows and not in Linux using Java

Question

Using Eclipse under windows I'm trying to split a text in two parts, the one from the start until the first line break and the rest of it

String[] result = resumen.split("\\R", 2);
String firstpart = result[0];
String rest = result[1];

Works ok.

But on a Linux machine I'm getting the error:

Exception in thread "main" java.util.regex.PatternSyntaxException: Illegal/unsupported escape sequence near index 1
\R

So I read somewhere on SO that I can use:

String[] result = resumen.split("\\\\R", 2);

But this does not work as expect and it doesnt split the sentence.

How can I adapt the code so it can work on a linux machine too?

Thanks in advance.

Also see RegEx in Java: how to deal with newline.

Wiktor Stribiżew
– Wiktor Stribiżew

2016-12-02 09:08:33 +00:00
Commented Dec 2, 2016 at 9:08 — Wiktor Stribiżew
– Wiktor Stribiżew, Commented Dec 2, 2016 at 9:08

T.J. Crowder · Accepted Answer · 2016-12-02 09:02:25Z

6

Sounds to me like the Linux machine has an older version of Java, and \R was added after that version.

\R is in Java 8. It's not in Java 7.

If you need to support Java 7, the docs say \R is equivalent to \u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029].

So based on that:

String[] result = resumen.split("\\u000D\\u000A|[\\u000A\\u000B\\u000C\\u000D\\u0085\\u2028\\u2029]", 2);

but I think we're okay if we supply those characters to the regex engine as literal characters rather than unicode escapes, so:

String[] result = resumen.split("\u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]", 2);

(but test that.)

edited Dec 2, 2016 at 9:02

answered Dec 2, 2016 at 8:57

T.J. Crowder

1.1m201 gold badges2k silver badges2k bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

T.J. Crowder Over a year ago

@XtremeBaumer: Not if the goal is to match line breaks cross-platform.

T.J. Crowder Over a year ago

@XtremeBaumer: Windows, but it's not so much platform as string contents. If you have a string with Windows-style linebreaks in it, splitting on \n will leave the \r in the resulting strings. And looking at the \R equivalent, there are more exotic line breaks as well.

XtremeBaumer Over a year ago

how come if i read a textfile with 2 lines and use System.out.print(line); i don't get 2 lines as output?

T.J. Crowder Over a year ago

@XtremeBaumer: It depends on how you're reading the file; sounds like line breaks were normalized. But again, it's about string contents. "foo\r\nbar".split("\\n")[0].length() is 4, not 3. "foo\r\nbar".split("\\R")[0].length() is 3 as desired.

infotoni91 Over a year ago

Why not using System.getProperty("line.separator") to get the right newline character?

Collectives™ on Stack Overflow

Simple regex working on Windows and not in Linux using Java

1 Answer 1

5 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related