Regex Expression for Java

Question

I am trying to extract out the content within the tags using regex expression in java listed below. I have been trying to get the paragraph context within the tags but can't get it out.

   Some text without tags here...
   <question1>
   Paragraph 1...

   Paragraph 2...

   </question1>
     Some text without tags here...
   <question2>

   Paragraph 1...

   Paragraph 2...
   </question2>
     Some text without tags here...

The above tags and contents are stored in a string variable: stringToSearch. The following are my codes.

Pattern p = Pattern.compile("<question1>(.*)</question1>");
Matcher a = p.matcher(stringToSearch);
                        System.out.print("\n Matching pattern...");
//                          Search the patterns in string
                            if (a.find()) {
                                String codeGroup = a.group(1);
                                System.out.format("'%s'\n", codeGroup);
                            }

However i am unable to get the tags which i suspect is due to the new lines that may appear within the Paragraphs. Reason for reg expression and not xml parser is due to the environment that i may have to use |question| |/question| or [[question]] [[/question]] special symbols.

It is content taken out from a email. Instead of using xml tags, i can use any unique tags such as [qn] context.... [/qn] — Jeremy Wong, Jun 26 '18 at 15:15
Mandatory reading: https://stackoverflow.com/a/1732454/66686 — Jens Schauder, Jun 26 '18 at 15:16

score 0 · Accepted Answer · answered Jun 26 '18 at 15:23

0

Pattern p = Pattern.compile("<question1>(.*)</question1>",Pattern.DOTALL);

answered Jun 26 '18 at 15:23

gagan singh

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Thank you very much Sir. I was missing the Pattern.DOTALL which i couldn't find. This works. – Jeremy Wong Jun 26 '18 at 15:32

Madushan Perera · Answer 2 · 2018-06-26T15:38:25.983

Your regex does not represent all the question(d) tags. Try something like below :

String stringToSearch = "Some text without tags here..."
                + "<question1>"
                + "   Paragraph 1..."
                + "   Paragraph 2..."
                + "</question1>"
                + "     Some text without tags here..."
                + "<question2>"
                + "   Paragraph 1..."
                + "   Paragraph 2..."
                + "</question2>"
                + "Some text without tags here...";

        Pattern pattern = Pattern.compile("<(\\w+)( +.+)*>((.*))</\\1>");

        Matcher matcher = pattern.matcher(stringToSearch);

        while (matcher.find()) {
            System.out.println(matcher.group(3));
        }

Alternatively you can use some xml parser libraries like jTopas ,jSoup to make it super easy.

Regex Expression for Java

2 Answers2