在Java中形成正则表达式以提取Wiki链接

Question

I am trying to write a Regex in java to find and extract all the wiki links starting with /wiki that occurs after the first occurrence of a paragraph tag in the html source code of a web page. For example

<a href="/wiki/Computer_scientist" title="Computer scientist">computer scientist</a> 
<p>Its fields can be divided into a variety of theoretical and <a href="/wiki/Practical_disciplines"

This should extract /wiki/Practical_disciplines

I am not much familiar with regular expressions but after doing some research what I have came up with is:

ArrayList<String> wikiLinks = new ArrayList<String>();
Pattern wikiPattern = Pattern.compile("^<p>([a-zA-Z0-9+&@/%?<>\"=~_|!,.;])+^(/wiki/[a-zA-Z0-9+&@/%?=~_|!,.;]+");
    Matcher wikiMatcher = wikiPattern.matcher("srcString");
    while (wikiMatcher.find()) {
        wikiLinks.add(srcString.substring(wikiMatcher.start(0),
            wikiMatcher.end(0)));

I know this is poorly formed and far from being even okay. But if somebody could help me formulate a regex for this or guide me in the right direction, I would really appreciate that.

Answer 1

You could use this regex ...

<p>.*?href=\"(.*?)\"

see regex demo / explanation

Java ( demo )

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

class RegEx {
    public static void main(String[] args) {
        String s = "<a href=\"/wiki/Computer_scientist\" title=\"Computer scientist\">computer scientist</a> <p>Its fields can be divided into a variety of theoretical and <a href=\"/wiki/Practical_disciplines\"";
        String r = "<p>.*?href=\"(.*?)\"";
        Pattern p = Pattern.compile(r);
        Matcher m = p.matcher(s);
        while (m.find()) {
            System.out.println(m.group(1));
        }
    }
}