builder.useUriResolver(new NaiveUserAgent.DefaultUriResolver() {
                @Override
                public String resolveURI(String baseUri, String uri) {
                    String inClassPath = FsPdfGenerator.localResource(uri);
                    if (null != inClassPath) {
                        logger.info("Loading from classpath: "+uri);
                        java.net.URL url = FsPdfGenerator.class.getResource('/' + inClassPath);
                        if (url != null)
                            return url.toExternalForm();
                    }
                    return super.resolveURI(baseUri, uri);
                }
            });

@Singleton
public class SimpleCache implements FSCache {
    private static final Logger logger = LoggerFactory.getLogger(SimpleCache.class);
    public static final int MAX_SIZE = 512;
    private final Map<FSCacheKey, Object> cache = lruCache(MAX_SIZE);
    private static <K,V> Map<K,V> lruCache(final int maxSize) {
        return new LinkedHashMap<K,V>(maxSize*4/3, 0.75f, true) {
            @Override
            protected boolean removeEldestEntry(Map.Entry<K,V> eldest) {
                return size() > maxSize;
            }
        };
    }
    private ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();
    public Object get(FSCacheKey cacheKey) {
        try {
            rwl.readLock().lock();
            Object obj = cache.get(cacheKey);
            if (logger.isDebugEnabled()) {
                logger.debug("Requesting: {} of type: {}, got it: {}", cacheKey.getUri(), cacheKey.getClazz().getName(), (obj != null));
            }
            return obj;
        } finally {
            rwl.readLock().unlock();
        }
    }
    public void put(FSCacheKey cacheKey, Object obj)  {
        try {
            rwl.writeLock().lock();
            if (logger.isDebugEnabled()) {
                logger.debug("Putting: {} of type: {}", cacheKey.getUri(), cacheKey.getClazz().getName());
            }
            cache.put(cacheKey, obj);
        } finally {
            rwl.writeLock().unlock();
        }
    }
}