Java Regex Problem

Question

I have as input text a big html file from where I have to extract some information using pattern matching. The "region" is somehow as follows:

 some html text
 <div debugState" style="display: none;">
            Model: ModelCode[BR324]
            Features: [S08TL, S0230, S0851, S0428, S01CD, S0879, S01CA, S08SP, S0698, S01CB, S0548, S08SC, S08TM, S01CC, S0801, S0258, P0668, S04AK]
            Packages: [S0801]
 </div>
        some html text

I wrote the following code. (At debInfo) is the html source to be scanned. Due to

Pattern model = Pattern.compile(".*(Model: ModelCode\\[\\w\\]).*, Pattern.DOTALL");
Pattern features = Pattern.compile(".*(Features: \\[\\w*\\]).*, Pattern.DOTALL");
Pattern packages = Pattern.compile(".*(Packages: \\[\\w*\\]).*, Pattern.DOTALL");


Matcher m1 = model.matcher(debInfo);
Matcher m2 = features.matcher(debInfo);
Matcher m3 = packages.matcher(debInfo);

boolean a = m1.matches();
boolean b = m2.matches();
boolean c = m3.matches();

System.out.println("matches(); " + a + " " + b + " " + c + " " + "\n" + debInfo);

and I am getting no match :-(. What am I doing wrong? Thanks in advance (a lot!)

Be aware that unless your HTML is in strict 7-bit ASCII, Java’s character class escapes will not work. That’s because they fail to meet requirement RL1.2a from UTS#18 Unicode Regular Expressions. It also fails to meet most of the other requirements for Basic Unicode Support. — tchrist
– tchrist, Commented Mar 21, 2011 at 18:55

Joachim Sauer · Accepted Answer · 2011-03-21 17:11:00Z

3

You use \\w inside your (correctly escaped) square brackets. That matches only a single character. Try \\w+ or \\w* instead.

Also, you have included , Pattern.DOTALL in your String literal, which I think is a typo:

Pattern model = Pattern.compile(".*(Model: ModelCode\\[\\w+\\]).*", Pattern.DOTALL);

Also note that for the comma-and-space separated list of Features \\w* will not work, you'll need something like [\\w\\s,]*.

edited Mar 21, 2011 at 17:11

answered Mar 21, 2011 at 17:04

Joachim Sauer

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1 Comment

Luixv Over a year ago

true, the "," was missing. It was a copy/paste problem, but that was not the problem. It was the MULTILINE switch what was missing.

Nr9 · Accepted Answer · 2011-03-21 17:12:52Z

2

I think you need to use:

Pattern model = Pattern.compile(".*(Model: ModelCode\\[\\w*\\]).*", Pattern.DOTALL);
Pattern features = Pattern.compile(".*(Features: \\[\\w*\\]).*", Pattern.DOTALL);
Pattern packages = Pattern.compile(".*(Packages: \\[\\w*\\]).*", Pattern.DOTALL);

edited Mar 21, 2011 at 17:12

answered Mar 21, 2011 at 17:05

Nr9

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2 Comments

Joachim Sauer Over a year ago

The * is missing in the first pattern.

Joachim Sauer Over a year ago

@Luixv: then your sample HTML is wrong, as it's got multiple characters at that point.

Luixv · Accepted Answer · 2011-03-23 13:44:57Z

1

These are the correct patterns:

Pattern modelPattern = Pattern.compile(".*Model: ModelCode\\[(\\w*)\\].*",
        Pattern.DOTALL | Pattern.MULTILINE);
Pattern featuresPattern = Pattern.compile(".*Features: \\[([\\w\\s,]*)\\].*",
        Pattern.DOTALL | Pattern.MULTILINE);
Pattern packagesPattern = Pattern.compile(".*Packages: \\[([\\w\\s,]*)\\].*",
        Pattern.DOTALL | Pattern.MULTILINE);

answered Mar 23, 2011 at 13:44

Luixv

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Comments

Luixv · Accepted Answer · 2011-03-21 17:19:04Z

0

It was missing the MULTILINE switch.

 Pattern modelPattern = Pattern.compile(".*(Model: ModelCode\\[\\w*\\]).*", Pattern.DOTALL | Pattern.MULTILINE);

answered Mar 21, 2011 at 17:19

Luixv

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1 Comment

Alan Moore Over a year ago

No, the MULTILINE flag changes the meaning of the anchors, ^ and $. You aren't using anchors in that regex, so MULTILINE has no effect.

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