How do I extract with non greedy across multiple lines in java regular expressions?

Question

If I have a bunch of data across multiple lines, how do I make it non greedy? What I have is greedy.

example data

</TD> 
<TD CLASS='statusEven'><TABLE BORDER=0 WIDTH='100%' CELLSPACING=0 CELLPADDING=0><TR><TD             ALIGN=LEFT><TABLE BORDER=0 CELLSPACING=0 CELLPADDING=0> 
<TR> 
<TD ALIGN=LEFT valign=center CLASS='statusEven'><A HREF='extinfo.cgi?    type=2&host=localhost&service=Current+Load'>Current Load</A></TD></TR> 
</TABLE> 
</TD> 
<TD ALIGN=RIGHT CLASS='statusEven'> 
<TABLE BORDER=0 cellspacing=0 cellpadding=0> 
<TR> 
</TR> 
</TABLE> 
</TD> 
</TR></TABLE></TD> 
<TD CLASS='statusOK'>OK</TD> 
<TD CLASS='statusEven' nowrap>08-04-2011 22:07:00</TD> 
<TD CLASS='statusEven' nowrap>28d 13h 18m 11s</TD> 
<TD CLASS='statusEven'>1/1</TD> 
<TD CLASS='statusEven' valign='center'>OK &#45; load average&#58; 0&#46;01&#44; 0&#46;04&#44; 0&#46;05&nbsp;</TD>

Here's my code so far

Pattern p = Pattern.compile("(?s)<TD ALIGN=LEFT valign=center CLASS(.*)?<TABLE");
Matcher m = p.matcher(this.resultHTML);

if(m.find())
{
     return m.group(1);
}

If I may advice, DO NOT parse HTML with regex. It won't work next week. Use HTML parser, like Neko. Or HTMLUnit. — Ondra Žižka, Aug 05 '11 at 02:43
you might want to read the reply in this thread, its funny and true http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags — KaKa, Aug 05 '11 at 02:47

score 3 · Accepted Answer · edited May 23 '17 at 11:59

3

Ungreedy:

Pattern.compile("(?s)<TD ALIGN=LEFT valign=center CLASS(.*?)?<TABLE");

Also, check this:

Java Regexp: UNGREEDY flag

I've implemented UNGREEDY for JDK's regex.

edited May 23 '17 at 11:59

Community

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answered Aug 05 '11 at 02:45

Ondra Žižka

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I upvoted your answer, but I also want to re-state what you mentioned in your excellent comment to the original question: ***Don't parse HTML with regex*** – Hovercraft Full Of Eels Aug 07 '11 at 15:27
@HovercraftFullOfEels what should I use then? – deadfish Feb 17 '16 at 17:22
@deadfish use a dedicated html parsing library – Hovercraft Full Of Eels Feb 17 '16 at 22:58

score 2 · Answer 2 · answered Aug 05 '11 at 04:47

To make a quantifier non-greedy, you add a question mark immediately after it:

.*    // greedy

.*?   // non-greedy

What you've got there - (.*)? - is a greedy .* in a capturing group, said group being optional (the ? is serving in its original role, as a zero-or-one quantifier).

How do I extract with non greedy across multiple lines in java regular expressions?

2 Answers2