Java Regex for Finding a Pattern and Getting Value in It?

Question

I am working on a plugin. I will parse HTML files. I have a naming convention like that:

<!--$include="a.html" -->

or

<!--$include="a.html"-->

is similar

According to this pattern(similar to server side includes) I want to search an HTML file. Question is that:

Find that pattern and get value (a.html at my example, it is variable)

It should be like:

while(!notFinishedWholeFile){
    fileName = findPatternFunc(htmlFile)
    replaceFunc(fileName,something)
}

PS: Using regex at Java or implementing it different(as like using .indexOf()) I don't know which one is better. If regex is good at this situation by performence I want to use it.

Any ideas?

Regular expressions don't perform replacement. They define search patterns. You have to do the replacing yourself. And of course once you've found what you want to replace you don't need another RE to define it. Not a real question. — user207421
– user207421, Commented Dec 30, 2012 at 19:28
You haven't add anything that changes the truth of my comment. You don't need two REs. — user207421
– user207421, Commented Dec 30, 2012 at 19:44

Muqito · Accepted Answer · 2012-12-30 19:28:57Z

0

You mean like this?

<!--\$include=\"(?<htmlName>[a-z-_]*).html\"\s?-->

answered Dec 30, 2012 at 19:28

Muqito

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3 Comments

kamaci Over a year ago

Do you mean: String pattern ="";

Muqito Over a year ago

@kamaci yes as the pattern. haven't tested it though. only with regex buddy for the two examples. you gave me.

kamaci Over a year ago

it doesn't find what I find

Community · Accepted Answer · 2017-05-23 12:18:46Z

0

Read a file into a string then

str = str.replaceAll("(?<=<!--\\$include=\")[^\"]+(?=\" ?-->)", something);

will replace the filenames with the string something, then the string can be written back to the file.
(Note: this replaces any text inside the double quotes, not just valid filenames.)

If you want only want to replace filenames with the html extension, swap the [^\"]+ for [^.]+.html.

Using regex for this task is fine performance wise, but see e.g. How to use regular expressions to parse HTML in Java? and Java Regex performance etc.

edited May 23, 2017 at 12:18

CommunityBot

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answered Dec 30, 2012 at 23:48

MikeM

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3 Comments

linski Over a year ago

quote from your links: "Using regular expressions to pull values from HTML is always a mistake." and: "Hint: Don't use regexes for link extraction or other HTML "parsing" tasks!" :)

MikeM Over a year ago

@linski. Yes, I included the links because I wanted kamaci to consider such opinions before making up his own mind.

linski Over a year ago

I thought it might be more visible, now that I have red it again it seems more obvious.

kamaci · Accepted Answer · 2013-02-18 20:01:25Z

0

I have used that pattern:

"<!--\\$include=\"(.+)(.)(html|htm)\"-->"

answered Feb 18, 2013 at 20:01

kamaci

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