[Q]What's wrong with this Pattern matching code?

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itsolution@gmail.com - 14 Jun 2006 08:15 GMT

Hi,

Pattern p=new Pattern("dialer%instance%.+%name");
Matcher matcher=p.matcher("dialer%instance%name");
System.out.print(matcher.matches()) ==> This prints 'true'!

How come, it matches? I expected e.g) "dialer%instance%1%name"
or "dialer%instance%1%name" would only match. But, why
"dialer%instance%name" also matches the pattern specified?

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Gordon Beaton - 14 Jun 2006 08:30 GMT

> Pattern p=new Pattern("dialer%instance%.+%name");
> Matcher matcher=p.matcher("dialer%instance%name");
> System.out.print(matcher.matches()) ==> This prints 'true'!
>
> How come, it matches?

Hard to say, since the code you tested isn't the code you posted.

For example, there is no public constructor for Pattern. After making
that correction, I get "false" as expected.

Post real, compilable code if you want a useful answer.

> I expected e.g) "dialer%instance%1%name" or "dialer%instance%1%name"
> would only match.

Did you mean to post two identical examples here?

> But, why "dialer%instance%name" also matches the pattern specified?

It doesn't.

/gordon

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Gijs Peek - 14 Jun 2006 08:30 GMT

Shouldn't you construct patterns like this:
Pattern p = Pattern.compile("dialer%instance%.+%name");

> Pattern p=new Pattern("dialer%instance%.+%name");
> Matcher matcher=p.matcher("dialer%instance%name");
> System.out.print(matcher.matches())

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Robert Klemme - 14 Jun 2006 08:31 GMT

> Hi,
>
> Pattern p=new Pattern("dialer%instance%.+%name");
> Matcher matcher=p.matcher("dialer%instance%name");
> System.out.print(matcher.matches()) ==> This prints 'true'!

No.

> How come, it matches? I expected e.g) "dialer%instance%1%name"
> or "dialer%instance%1%name" would only match. But, why
> "dialer%instance%name" also matches the pattern specified?

You're confused. Your code doesn't even compile.

robert

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itsolution@gmail.com - 14 Jun 2006 17:50 GMT

Oops, some errta correction.

Pattern p=new Pattern.compile("dialer%instance%.+%name");
Matcher matcher=p.matcher("dialer%instance%name");
System.out.print(matcher.matches()) ==> This prints 'true'!

How come, it matches? I expected e.g) "dialer%instance%1%name"
or "dialer%instance%2%name" would only match. But, why
"dialer%instance%name" also matches the pattern specified?

> Hi,
>
[quoted text clipped - 5 lines]
> or "dialer%instance%1%name" would only match. But, why
> "dialer%instance%name" also matches the pattern specified?

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Robert Klemme - 14 Jun 2006 18:00 GMT

> Oops, some errta correction.
>
> Pattern p=new Pattern.compile("dialer%instance%.+%name");
> Matcher matcher=p.matcher("dialer%instance%name");
> System.out.print(matcher.matches()) ==> This prints 'true'!

You're still confused. Go away.

robert

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Hendrik Maryns - 14 Jun 2006 18:21 GMT

itsolution@gmail.com schreef:

> Oops, some errta correction.
>
[quoted text clipped - 5 lines]
> or "dialer%instance%2%name" would only match. But, why
> "dialer%instance%name" also matches the pattern specified?

You code still does not compile. Remove ‘new’, and try it out first if
you post again in the future.

H.

- --
Hendrik Maryns

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Patricia Shanahan - 14 Jun 2006 19:00 GMT

> Oops, some errta correction.
>
[quoted text clipped - 5 lines]
> or "dialer%instance%2%name" would only match. But, why
> "dialer%instance%name" also matches the pattern specified?

Rather than posting errata, it seems to be time for a Short,
Self-Contained, Compilable Example (SSCCE). I tried to construct one
from the snippet you posted. I had edit out "new " to get it to compile,
so I know what you posted is not what you are running. This program
prints "false", so some difference from what you are running is
significant.

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class PatternTest {
public static void main(String[] args) {
Pattern p=Pattern.compile("dialer%instance%.+%name");
Matcher matcher=p.matcher("dialer%instance%name");
System.out.print(matcher.matches());
}
}

Your best bet for getting help is to edit this example to make it match
what you are doing, and post the new version. Make sure you copy-paste,
with no retyping, when you post it, so that the program in the message
is EXACTLY the program you are running.

Keep the form of a very short but complete program. Anyone who wants to
help you should be able to copy-paste the program from your message into
their favorite Java editor and reproduce your problem without having to
add, delete, or change a single byte.

Patricia

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[Q]What's wrong with this Pattern matching code?

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