ResourceList.java

package com.weem.epicinventor.utility;

import java.util.*;
import java.io.*;
import java.util.jar.*;

/**
 * list resources available from the classpath @ *
 */
public class ResourceList {

    public static String[] getResourceListing(Class c, String path) throws Exception {
        java.net.URL dirURL = c.getResource(path);
        if (dirURL != null && dirURL.getProtocol().equals("file")) {
            /* A file path: easy enough */
            return new File(dirURL.toURI()).list();
        }

        if (dirURL == null) {
            /*
             * In case of a jar file, we can't actually find a directory.
             * Have to assume the same jar as clazz.
             */
            String me = c.getName().replace(".", "/") + ".class";
            dirURL = c.getClassLoader().getResource(me);
        }

        if (dirURL.getProtocol().equals("jar")) {
            /* A JAR path */
            String jarPath = dirURL.getPath().substring(5, dirURL.getPath().indexOf("!")); //strip out only the JAR file
            JarFile jar = new JarFile(java.net.URLDecoder.decode(jarPath, "UTF-8"));
            Enumeration<JarEntry> entries = jar.entries(); //gives ALL entries in jar
            Set<String> result = new HashSet<String>(); //avoid duplicates in case it is a subdirectory
            while (entries.hasMoreElements()) {
                String name = entries.nextElement().getName();
                if (name.startsWith(path)) { //filter according to the path
                    String entry = name.substring(path.length());
                    int checkSubdir = entry.indexOf("/");
                    if (checkSubdir >= 0) {
                        // if it is a subdirectory, we just return the directory name
                        entry = entry.substring(0, checkSubdir);
                    }
                    result.add(entry);
                }
            }
            return result.toArray(new String[result.size()]);
        }

        throw new UnsupportedOperationException("Cannot list files for URL " + dirURL);
    }
}