import org.codelibs.core.lang.StringUtil;

/**
 * EncodingHelper provides utility methods for managing and normalizing character encodings.
 * It allows setting a default encoding, mapping various encoding names to preferred ones,
 * and normalizing an encoding string to its preferred form or the default if no mapping is found.
 */
public class EncodingHelper {

    /** The default encoding to use when no mapping is found */

 */
public class EncodingHelperTest extends PlainTestCase {
    public EncodingHelper encodingHelper;

    @Override
    protected void setUp() throws Exception {
        super.setUp();
        StandardCrawlerContainer container = new StandardCrawlerContainer().singleton("encodingHelper", EncodingHelper.class);
        encodingHelper = container.getComponent("encodingHelper");
    }

    public void test_normalize() {
        String enc;

<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components namespace="fessCrawler">
	<include path="crawler/container.xml" />

	<component name="encodingHelper" class="org.codelibs.fess.crawler.helper.EncodingHelper">
		<postConstruct name="addEncodingMapping">
			<arg>"unicode"</arg>
			<arg>"UTF-16LE"</arg>
		</postConstruct>
	</component>

     * @return the normalized encoding name
     */
    protected String normalizeEncoding(final String encoding) {
        try {
            final EncodingHelper encodingHelper = crawlerContainer.getComponent("encodingHelper");
            return encodingHelper.normalize(encoding);
        } catch (final Exception e) {
            // NOP
        }
        return encoding;
    }

    /**

                .singleton("sitemapsHelper", SitemapsHelper.class)
                .singleton("logHelper", LogHelperImpl.class)
                .singleton("encodingHelper", EncodingHelper.class)
                .singleton("contentLengthHelper", ContentLengthHelper.class)
                .singleton("mimeTypeHelper", MimeTypeHelperImpl.class)

```

### Helpers

**RobotsTxtHelper**: RFC 9309 parsing, user-agent matching, crawl-delay, sitemaps
**SitemapsHelper**: Sitemap XML parsing, index handling
**MimeTypeHelper**: MIME detection via Tika
**EncodingHelper**: Charset detection with BOM
**UrlConvertHelper**: URL normalization

---

## Development Workflow

### Build Commands

```bash
mvn clean install              # Build all