RegEx for matching mp3 URLs

Question

How can I get an mp3 url with REGEX?

This mp3 url, for example:

https://www.soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3

This is a what I've tried so far but I want it to only accept a url with '.mp3' on the end.

(https?|ftp|file)://[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]

Answer 1

This expression would likely pass your desired inputs:

^(https?|ftp|file):\/\/(www.)?(.*?)\.(mp3)$

If you wish to add more boundaries to it, you can do that. For instance, you can add a list of chars instead of .*.

I have added several capturing groups, just to be simple to call, if necessary.

RegEx

If this wasn't your desired expression, you can modify/change your expressions in regex101.com.

RegEx Circuit

You can also visualize your expressions in jex.im:

const regex = /^(https?|ftp|file):\/\/(www.)?(.*?)\.(mp3)$/gm;
const str = `https://www.soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3
http://soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3
http://www.soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3
ftp://soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3
file://localhost/examples/mp3/SoundHelix-Song-1.mp3
file://localhost/examples/mp3/SoundHelix-Song-1.wav
file://localhost/examples/mp3/SoundHelix-Song-1.avi
file://localhost/examples/mp3/SoundHelix-Song-1.m4a`;
let m;

while ((m = regex.exec(str)) !== null) {
    // This is necessary to avoid infinite loops with zero-width matches
    if (m.index === regex.lastIndex) {
        regex.lastIndex++;
    }
    
    // The result can be accessed through the `m`-variable.
    m.forEach((match, groupIndex) => {
        console.log(`Found match, group ${groupIndex}: ${match}`);
    });
}

Java Test

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

final String regex = "^(https?|ftp|file):\\/\\/(www.)?(.*?)\\.(mp3)$";
final String string = "https://www.soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3\n"
     + "http://soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3\n"
     + "http://www.soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3\n"
     + "ftp://soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3\n"
     + "file://localhost/examples/mp3/SoundHelix-Song-1.mp3\n"
     + "file://localhost/examples/mp3/SoundHelix-Song-1.wav\n"
     + "file://localhost/examples/mp3/SoundHelix-Song-1.avi\n"
     + "file://localhost/examples/mp3/SoundHelix-Song-1.m4a";

final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE);
final Matcher matcher = pattern.matcher(string);

while (matcher.find()) {
    System.out.println("Full match: " + matcher.group(0));
    for (int i = 1; i <= matcher.groupCount(); i++) {
        System.out.println("Group " + i + ": " + matcher.group(i));
    }
}