// Test empty pattern
        urlFilter.addInclude("");
        urlFilter.addExclude("");

        // Test single character pattern
        urlFilter.addInclude(".");
        urlFilter.addExclude("*");

        // Test patterns with only special characters
        urlFilter.addInclude("^$");
        urlFilter.addExclude(".*");

        // Should handle boundary conditions gracefully

     */
    protected UrlFilterService urlFilterService;

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.filter.UrlFilter#addExclude(java.lang.String)
     */
    @Override
    public void addExclude(final String urlPattern) {
        try {
            Pattern.compile(urlPattern);
        } catch (final Exception e) {
            if (logger.isWarnEnabled()) {

```

### URL Filtering

```java
// Include patterns
crawler.urlFilter.addInclude("https://example.com/.*");
crawler.urlFilter.addInclude(".*\\.pdf$");

// Exclude patterns  
crawler.urlFilter.addExclude(".*\\.js$");
crawler.urlFilter.addExclude(".*login.*");
```

## Supported Protocols and Formats

### Protocols

        crawler.crawlerContext.setMaxAccessCount(maxCount);
        crawler.crawlerContext.setNumOfThread(numOfThread);
        crawler.urlFilter.addInclude(url + ".*");
        crawler.urlFilter.addExclude(url + "/dir1/.*");
        final String sessionId = crawler.execute();
        assertEquals(maxCount, dataService.getCount(sessionId));
        dataService.delete(sessionId);
    }

     */
    public void addExcludeFilter(final String regexp) {
        if (StringUtil.isNotBlank(regexp)) {
            urlFilter.addExclude(regexp);
        }
    }

    /**
     * Stops the crawling process.
     * Sets the crawler status to DONE and interrupts all crawler threads.
     */
    public void stop() {
        crawlerContext.setStatus(CrawlerStatus.DONE);
        try {

        crawler.crawlerContext.setMaxAccessCount(maxCount);
        crawler.crawlerContext.setNumOfThread(numOfThread);
        crawler.urlFilter.addInclude(url + ".*");
        crawler.urlFilter.addExclude(url + "/dir1/.*");
        final String sessionId = crawler.execute();
        assertEquals(maxCount, dataService.getCount(sessionId));
        dataService.delete(sessionId);
    }

        @Override
        public void init(String sessionId) {
        }

        @Override
        public void addInclude(String urlPattern) {
        }

        @Override
        public void addExclude(String urlPattern) {
        }

        @Override
        public boolean match(String url) {
            return true;
        }

        @Override

                                        final String urlValue = hostUrl + urlPattern;
                                        crawlerContext.getUrlFilter().addExclude(urlValue);
                                        if (logger.isInfoEnabled()) {
                                            logger.info("Excluded URL: {}", urlValue);
                                        }

    public ArtifactFilter getArtifactFilter() {
        Set<String> excludes = new LinkedHashSet<>(getExcludedArtifacts());

        for (ArtifactFilterManagerDelegate delegate : delegates) {
            delegate.addExcludes(excludes);
        }

        return new ExclusionSetFilter(excludes);
    }

    /**
     * Returns the artifact filter for the standard core artifacts.
     *

            crawler.addUrl(url);
            crawler.getCrawlerContext().setMaxAccessCount(maxCount);
            crawler.getCrawlerContext().setNumOfThread(numOfThread);
            crawler.urlFilter.addInclude(url + ".*");
            final String sessionId = crawler.execute();
            assertEquals(maxCount, dataService.getCount(sessionId));
            dataService.delete(sessionId);
        } finally {