Class ClassLoaders

api/src/main/java/org/apache/sirona/util/ClassLoaders.java:30–193

import java.util.Set;

public class ClassLoaders {
    private static final boolean DONT_USE_GET_URLS = Boolean.getBoolean("xbean.finder.use.get-resources");
    private static final ClassLoader SYSTEM = ClassLoader.getSystemClassLoader();
    private static final boolean UNIX = !System.getProperty("os.name").toLowerCase().contains("win");
    private static final URL[] NO_URL = new URL[0];

    public static ClassLoader current() {
        final ClassLoader tccl = Thread.currentThread().getContextClassLoader();
        if (tccl != null) {
            return tccl;
        }
        return ClassLoaders.class.getClassLoader();
    }

    public static URL[] findUrls(final ClassLoader classLoader) throws IOException {
        if (classLoader == null || (SYSTEM.getParent() != null && classLoader == SYSTEM.getParent())) {
            return NO_URL;
        }

        final Set<URL> urls =  new HashSet<URL>();

        if (URLClassLoader.class.isInstance(classLoader) && !DONT_USE_GET_URLS) {
            if (!isSurefire(classLoader)) {
                for (final URL[] item : new URL[][] { URLClassLoader.class.cast(classLoader).getURLs(), findUrls(classLoader.getParent()) }) {
                    for (final URL url : item) {
                        addIfNotSo(urls, url);
                    }
                }
            } else { // http://jira.codehaus.org/browse/SUREFIRE-928 - we could reuse findUrlFromResources but this seems faster
                urls.addAll(fromClassPath());
            }
        }

        // DONT_USE_GET_URLS || java -jar xxx.jar and use MANIFEST.MF Class-Path?
        // here perf is not an issue since we would either miss all the classpath or we have a single jar
        if (urls.size() <= 1) {
            final Set<URL> urlFromResources = findUrlFromResources(classLoader);
            if (!urls.isEmpty()) {
                final URL theUrl = urls.iterator().next();
                if ("file".equals(theUrl.getProtocol())) {  // theUrl can be file:xxxx but it is the same entry actually
                    urlFromResources.remove(new URL("jar:" + theUrl.toExternalForm() + "!/"));
                }
            }
            urls.addAll(urlFromResources);
        }

        return urls.toArray(new URL[urls.size()]);
    }

    private static void addIfNotSo(final Set<URL> urls, final URL url) {
        if (UNIX && isNative(url)) {
            return;
        }

        urls.add(url);
    }

    public static boolean isNative(final URL url) {