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Thread: Java Regex Help

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    Default Java Regex Help

    I'm currently learning regular expressions, and one of my tasks is to get all text between <body> and </body> of a html file. When <body> and </body> are on the same line I get a result, but the contents of body is supposed to span across multiple lines which in that instance, doesn't return anything as its only checking the one full line?.

    What I don't understand is, where in this regex could I put a new line ?
    String regex = "<body>.*?</body>"
    also, what new line expression should I use? as I've seen examples such as:
    \n \\n '\n' ('\u000A')

    Thanks.

    Any good tutorials would be appreciated as an alternative
    Last edited by newbie; January 25th, 2011 at 05:38 PM.
    Please use [highlight=Java]//code goes here...[/highlight] tags when posting your code


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    Super Moderator copeg's Avatar
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    Default Re: Java Regex Help

    By default, a dot (".") in a regular expression excludes new lines. Pass Pattern.DOTALL to the Pattern compiler to have dots represent all plus new lines
    Pattern patter = Pattern.compile(regex, Pattern.DOTALL);
    Last edited by copeg; January 25th, 2011 at 06:18 PM.

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    Default Re: Java Regex Help

    Hmm yeah thanks for that, The description of pattern = Pattern.compile(regex, Pattern.DOTALL);
    seems to be what I was after, but unfortunately, It still fails to find a match when <body> and </body> are on different lines.
    Please use [highlight=Java]//code goes here...[/highlight] tags when posting your code

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    Default Re: Java Regex Help

    You will have to post an example then (both code and text to parse) that does not work, as it works for me...

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    Default Re: Java Regex Help

    ----VOID----
    Last edited by newbie; February 6th, 2011 at 02:02 PM.
    Please use [highlight=Java]//code goes here...[/highlight] tags when posting your code

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    Default Re: Java Regex Help

    This isn't a problem with the regular expression per se, but how the file is read. If you wish to search for a regular expression across the file, you should read the file in full, and then pass the contents into the regular expression engine. As of right now, you are reading using a scanner, which delims on whitespace, so you feed the regular expression engine the contents of the file word by word, and will never find the body tags.

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    newbie (January 26th, 2011)

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    Default Re: Java Regex Help

    Please use [highlight=Java] code [/highlight] tags when posting your code.
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    newbie (January 26th, 2011)

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    Default Re: Java Regex Help

    Thank you both for your input, I read the file into a StringBuilder, then searched that, which worked a treat
    Please use [highlight=Java]//code goes here...[/highlight] tags when posting your code

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