Locates a file inside your resources whether they are in a "normal" resource directory or inside a jar - untested, for reference only

ResourceFileResolver.java

package com.acme.example;

import com.sun.javaws.Launcher;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Enumeration;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

/**
 * Created with IntelliJ IDEA.
 * User: moshee
 * Date: 31/12/13
 * Time: 18:36
 */
public class ResourceFileResolver {

    private final Logger logger = LoggerFactory.getLogger(JavascriptResourceFileResolver.class);
    public boolean checkIfResourceFileExists(String path, String fileInternalPath) {
        try {
        final File jarFile = new File(getClass().getProtectionDomain().getCodeSource().getLocation().getPath());

        if(jarFile.isFile()) {  // Run with JAR file
            try {
            final JarFile jar = new JarFile(jarFile);
            final Enumeration<JarEntry> entries = jar.entries(); //gives ALL entries in jar
            while(entries.hasMoreElements()) {
                final String name = entries.nextElement().getName();
                if (name.startsWith(path + "/") && name.endsWith(fileInternalPath)) { //filter according to the path
                    return true;
                }
            }
            jar.close();
            } catch (IOException exp) {
                logger.error("Problem with requested js file: " + path, exp);
            }
        } else { // Run with IDE
            final URL url = Launcher.class.getResource("/" + path + "/" + fileInternalPath);
            if (url != null) {
                try {
                    final File apps = new File(url.toURI());
                    return true;
                } catch (URISyntaxException ex) {
                    // never happens
                }
            }
        }
        } catch (Exception exp) {
            logger.error("Problem with requested js file: " + fileInternalPath, exp);
        }
        return false;

    }
}