// 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

        this.originalSourceRoot = sourceRoot;
        this.scope = scope;
        this.project = project;
    }

    @Override
    public void addInclude(String include) {
        // Update the underlying Resource model
        super.addInclude(include);

        // Update the project's SourceRoots
        updateProjectSourceRoot();
    }

    @Override
    public void removeInclude(String include) {

        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);
    }

    }

    @Test
    void testAddMultipleIncludes() {
        Resource resource = project.getResources().get(0);

        // Add multiple includes
        resource.addInclude("*.xml");
        resource.addInclude("*.properties");

        // Verify both includes are present
        assertEquals(2, resource.getIncludes().size(), "Should have two includes");

        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);
    }

        }
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.filter.UrlFilter#addInclude(java.lang.String)
     */
    @Override
    public void addInclude(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.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 {

     * @param regexp The regular expression for the include filter.
     */
    public void addIncludeFilter(final String regexp) {
        if (StringUtil.isNotBlank(regexp)) {
            urlFilter.addInclude(regexp);
        }
    }

    /**
     * Adds an exclude filter for URLs.
     * URLs matching this regular expression will not be crawled.
     * @param regexp The regular expression for the exclude filter.

3. **Add test with sample file** in `src/test/resources/`

### Configuring URL Filtering

```java
// Include patterns (must match)
crawler.urlFilter.addInclude("https://example.com/.*");

// Exclude patterns (must not match)
crawler.urlFilter.addExclude(".*\\.(css|js|png|jpg)$");
```

### Setting Crawl Limits

```java
context.setMaxAccessCount(1000);  // Max URLs (0 = unlimited)