Extract substring from string - regex

Question

I have a String say:

<encoded:2,Message request>

Now I want to extract 2 and Message request from the line above.

private final String pString = "<encoded:[0-9]+,.*>";
    private final Pattern pattern = Pattern.compile(pString);

    private void parseAndDisplay(String line) {

        Matcher matcher = pattern.matcher(line);
        if (matcher.matches()) {
            while(matcher.find()) {
                String s = matcher.group();
                System.out.println("=====>"+s);

            }
        }
    }

This doesn't retrieve it. What is wrong with it

hsz · Accepted Answer · 2013-03-25 09:58:45Z

6

You have to define groups in your regex:

"<encoded:([0-9]+),(.*?)>"

or

"<encoded:(\\d+),([^>]*)"

edited Mar 25, 2013 at 9:58

answered Mar 25, 2013 at 9:44

hsz

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3 Comments

Pshemo Over a year ago

In Java to pass \ literal it must be written as \\. So \d should be \\d. Anyway +1.

Pshemo Over a year ago

@Jatin you need to capture groups. Instead group() use group(1) and group(2).

zx81 Over a year ago

+1 for showing two options—lazy quantifier or negated character class.

Evgeniy Dorofeev · Accepted Answer · 2013-03-25 10:01:39Z

3

try

    String s = "<encoded:2,Message request>";
    String s1 = s.replaceAll("<encoded:(\\d+?),.*", "$1");
    String s2 = s.replaceAll("<encoded:\\d+?,(.*)>", "$1");

edited Mar 25, 2013 at 10:01

answered Mar 25, 2013 at 9:53

Evgeniy Dorofeev

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6 Comments

MozenRath Over a year ago

better to use replaceFirst?

Evgeniy Dorofeev Over a year ago

It works too, but I dont think it makes any difference in this situation

MozenRath Over a year ago

if message request contained a similar innner tag, it would fail right?

Evgeniy Dorofeev Over a year ago

tested "<encoded:2,Message > request>" s2 returns "Message > request"

Evgeniy Dorofeev Over a year ago

Sure, in this case replaceAll won't work, we will need to use Matcher.find

|

MozenRath · Accepted Answer · 2013-03-25 09:48:38Z

0

Try

"<encoded:([0-9]+),([^>]*)"

Also, as suggested in other comments, use group(1) and group(2)

answered Mar 25, 2013 at 9:48

MozenRath

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Comments

Ankur Shanbhag · Accepted Answer · 2013-03-25 09:58:43Z

0

Try this out :

         Matcher matcher = Pattern.compile("<encoded:(\\d+)\\,([\\w\\s]+)",Pattern.CASE_INSENSITIVE).matcher("<encoded:2,Message request>");

    while (matcher.find()) {
        System.out.println(matcher.group(1));
        System.out.println(matcher.group(2));
    }

answered Mar 25, 2013 at 9:58

Ankur Shanbhag

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