substring between two delimiters

Question

I have a string as : "This is a URL http://www.google.com/MyDoc.pdf which should be used"

I just need to extract the URL that is starting from http and ending at pdf : http://www.google.com/MyDoc.pdf

String sLeftDelimiter = "http://";
String[] tempURL = sValueFromAddAtt.split(sLeftDelimiter );
String sRequiredURL = sLeftDelimiter + tempURL[1];

This gives me the output as "http://www.google.com/MyDoc.pdf which should be used"

Need help on this.

Related to this question, please check it out: [How to detect the presence of URL in a string][1] [1]: http://stackoverflow.com/questions/285619/how-to-detect-the-presence-of-url-in-a-string — Crazenezz, Apr 16 '12 at 08:50

score 12 · Accepted Answer · answered Apr 16 '12 at 08:57

12

This kind of problem is what regular expressions were made for:

Pattern findUrl = Pattern.compile("\\bhttp.*?\\.pdf\\b");
Matcher matcher = findUrl.matcher("This is a URL http://www.google.com/MyDoc.pdf which should be used");
while (matcher.find()) {
  System.out.println(matcher.group());
}

The regular expression explained:

\b before the "http" there is a word boundary (i.e. xhttp does not match)
http the string "http" (be aware that this also matches "https" and "httpsomething")
.*? any character (.) any number of times (*), but try to use the least amount of characters (?)
\.pdf the literal string ".pdf"
\b after the ".pdf" there is a word boundary (i.e. .pdfoo does not match)

If you would like to match only http and https, try to use this instead of http in your string:

https?\: - this matches the string http, then an optional "s" (indicated by the ? after the s) and then a colon.

answered Apr 16 '12 at 08:57

nd.

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Thanks a lot..this one really helped...as the text before after the url can be anything , so this regex for extracting the URL is what i needed. – SMA_JAVA Apr 16 '12 at 09:06
If you want to support arbitrary strings that are either URLs or strings that look like URLs but don't have a protocol handler (e.g. www.foo.com), then use Gruber's regular expression http://daringfireball.net/2010/07/improved_regex_for_matching_urls – nd. Apr 16 '12 at 09:13
Thanks for crisp answer ....I used as : Pattern findUrl = Pattern.compile("\\bversion-.*?\\.0.0\\b"); Matcher matcher = findUrl.matcher(response.toString()); if (matcher.find()) { System.out.println(matcher.group().substring(10,13)); // to get the substring } – Shashank Bodkhe Jan 10 '19 at 07:46

score 1 · Answer 2 · answered Apr 16 '12 at 08:43

1

why don't you use startsWith("http://") and endsWith(".pdf") mthods of String class.

Both the method returns boolean value, if both returns true, then your condition succeed else your condition is failed.

answered Apr 16 '12 at 08:43

Chandra Sekhar

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The question states that he has a string which contains "This is a URL `URL` which should be used". I don't see how `startsWith()` and `endsWith()` are applicable here. – Arvindh Mani Mar 19 '17 at 06:13

score 1 · Answer 3 · answered Apr 16 '12 at 08:51

1

Try this

String StringName="This is a URL http://www.google.com/MyDoc.pdf which should be used";

StringName=StringName.substring(StringName.indexOf("http:"),StringName.indexOf("which"));

answered Apr 16 '12 at 08:51

Nishant

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'which' may appear several times and before 'http:' – Oleg Vazhnev Sep 30 '21 at 00:11

score 0 · Answer 4 · answered Apr 16 '12 at 09:05

You can use Regular Expression power for here. First you have to find Url in original string then remove other part.

Following code shows my suggestion:

    String regex = "\\b(http|ftp|file)://[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]";
    String str = "This is a URL http://www.google.com/MyDoc.pdf which should be used";

    String[] splited = str.split(regex);

    for(String current_part : splited)
    {
        str = str.replace(current_part, "");
    }

    System.out.println(str);

This snippet code cans retrieve any url in any string with any pattern. You cant add customize protocol such as https to protocol part in above regular expression.

I hope my answer help you ;)

Please note that this pattern does not match internationalized domain names such as http://مثال.إختبار — nd., Apr 17 '12 at 11:42

score 0 · Answer 5 · answered Jul 28 '16 at 23:40

public static String getStringBetweenStrings(String aString, String aPattern1, String aPattern2) {
    String ret = null;
    int pos1,pos2;

    pos1 = aString.indexOf(aPattern1) + aPattern1.length();
    pos2 = aString.indexOf(aPattern2);

    if ((pos1>0) && (pos2>0) && (pos2 > pos1)) {
        return aString.substring(pos1, pos2);
    }

    return ret;
}

score 0 · Answer 6 · answered Jun 07 '18 at 17:48

You can use String.replaceAll with a capturing group and back reference for a very concise solution:

String input = "This is a URL http://www.google.com/MyDoc.pdf which should be used";
System.out.println(input.replaceAll(".*(http.*?\\.pdf).*", "$1"));

Here's a breakdown for the regex: https://regexr.com/3qmus

substring between two delimiters

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