Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
    /**
     * Extract the UUID part from a MusicBrainz identifier.
     * 
     * This function takes a MusicBrainz ID (an absolute URI) as the input
     * and returns the UUID part of the URI, thus turning it into a relative
     * URI. If <code>uriStr</code> is null or a relative URI, then it is
     * returned unchanged.
     * 
     * The <code>resType</code> parameter can be used for error checking.
     * Set it to 'artist', 'release', or 'track' to make sure 
     * <code>uriStr</code> is a syntactically valid MusicBrainz identifier
     * of the given resource type. If it isn't, an 
     * <code>IllegalArgumentException</code> exception is raised. This error
     * checking only works if <code>uriStr</code> is an absolute URI, of course.
     * 
     * Example:
     * >>>  MBUtils.extractUuid('http://musicbrainz.org/artist/c0b2500e-0cef-4130-869d-732b23ed9df5', 'artist')
     * 'c0b2500e-0cef-4130-869d-732b23ed9df5'
     * 
     * @param uriStr A string containing a MusicBrainz ID (an URI), or null
     * @param resType A string containing a resource type
     * @return A String containing a relative URI or null
     * @throws URISyntaxException 
     */
    public static String extractUuid(String uriStr, String resType) {
        if (uriStr == null) {
            return null;
        }

        URI uri;
        try {
            uri = new URI(uriStr);
        } catch (URISyntaxException e) {
            return uriStr; // not really a valid URI, probably the UUID
        }
        if (uri.getScheme() == null) {
            return uriStr; // not really a valid URI, probably the UUID
        }

        if (!"http".equals(uri.getScheme()) || !"musicbrainz.org".equals(uri.getHost())) {
            throw new IllegalArgumentException(uri.toString() + " is no MB ID");
        }

        String regex = "^/(label|artist|release-group|release|recording|work|collection)/([^/]*)$";
        Pattern p = Pattern.compile(regex);
        Matcher m = p.matcher(uri.getPath());
        if (m.matches()) {
            if (resType == null) {
                return m.group(2);
            } else {
                if (resType.equals(m.group(1))) {
                    return m.group(2);
                } else {
                    throw new IllegalArgumentException("expected '" + resType + "' Id");
                }
            }
        } else {
            throw new IllegalArgumentException("'" + uriStr + " is no valid MB id");
        }
    }
}