regex doesn't match multiple strings

Question

I am trying to find multiple matches in my regex. Here is my regex

final Pattern p = Pattern.compile("^[0-9]{8}[#](FRI|SAT|SUN)[\r]$");
final Matcher m = p.matcher("09042012#SUN\r" + "09022012#FRI\r" + "09032012#SAT\r");
    while (m.find())
    {
        final String result = m.group();
        System.out.println(result);
    }

this works if the string has just one match, but if its consecutive matches it doesn't work. I have tried adding .+ at the end of my regex to make sure it atleast have one match. That doesn't work either.

What am I doing wrong??

Darth Android · Accepted Answer · 2016-04-08 19:06:55Z

2

You need to set the multiline flag:

final Pattern p = Pattern.compile("^[0-9]{8}[#](FRI|SAT|SUN)$", Pattern.MULTILINE);

This will allow the $ and ^ to match on the carriage returns \r in your input.

answered Apr 8, 2016 at 19:06

Darth Android

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Comments

Pshemo · Accepted Answer · 2016-04-08 19:15:14Z

^ and $ by default represent start/end of entire input (passed to Matcher), not start/end of lines.

If you want your regex to match only lines use in your regex Pattern.MULTILINE flag.
Also remove [\r] since characters after it are considered as placed in next line which means that $ placed after [\r] can only match end of next line - in other words you would find only match which have next line empty.

So your code should look more like

final Pattern p = Pattern.compile("^[0-9]{8}[#](FRI|SAT|SUN)$", Pattern.MULTILINE);
//                                                              ^^^^^^^^^^^^^^^^^
final Matcher m = p.matcher(
          "09042012#SUN\r" 
        + "09022012#FRI\r" 
        + "09032012#SAT\r");
while (m.find())
{
    final String result = m.group();
    System.out.println(result);
}

Quinn · Accepted Answer · 2016-04-08 19:19:19Z

0

Remove line start ^ and line end $, your code would work:

final Pattern p = Pattern.compile("[0-9]{8}[#](FRI|SAT|SUN)[\r]");
final Matcher m = p.matcher("09042012#SUN\r" + "09022012#FRI\r" + "09032012#SAT\r");
    while (m.find())
    {
        final String result = m.group();
        System.out.println(result);
    }

answered Apr 8, 2016 at 19:19

Quinn

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