fess-crawler-parent/
├── fess-crawler/              # Core crawler framework
│   ├── client/               # Protocol clients (HTTP, FTP, SMB, etc.)
│   ├── extractor/           # Content extractors
│   ├── transformer/         # Data transformers
│   └── service/             # Core services
├── fess-crawler-lasta/       # LastaFlute DI integration
└── fess-crawler-opensearch/  # OpenSearch backend
```

### Key Components

                accessResult.setAccessResultData(null);
                try {
                    final Transformer transformer = ComponentUtil.getComponent(accessResultData.getTransformerName());
                    if (transformer == null) {
                        // no transformer
                        logger.warn("Transformer not found: name={}, url={}", accessResultData.getTransformerName(), accessResult.getUrl());

        TestTransformer transformer3 = new TestTransformer("transformer3");

        ResponseData responseData = new ResponseData();
        responseData.setUrl("http://example.com");

        ResultData result1 = transformer1.transform(responseData);
        ResultData result2 = transformer2.transform(responseData);
        ResultData result3 = transformer3.transform(responseData);

        TestTransformer transformer1 = new TestTransformer();
        NameTrackingTransformer transformer2 = new NameTrackingTransformer();

        transformer1.setName("transformer1");
        transformer2.setName("transformer2");

        assertEquals("transformer1", transformer1.getName());
        assertEquals("transformer2", transformer2.getName());

 * <p>
 * The {@link #getData(AccessResultData)} method allows retrieving the transformed data as a String (XML content),
 * a Map, or an instance of a specified class.
 * </p>
 *
 * <p>
 * Example usage:
 * </p>
 *
 * <pre>
 * XpathTransformer transformer = new XpathTransformer();
 * transformer.addFieldRule("title", "//title/text()");
 * transformer.addFieldRule("body", "//body/p/text()");
 *

    }

    /**
     * Gets the transformer.
     *
     * @return the transformer
     */
    public Transformer getTransformer() {
        return transformer;
    }

    /**
     * Sets the transformer.
     *
     * @param transformer the transformer to set
     */
    public void setTransformer(final Transformer transformer) {
        this.transformer = transformer;
    }

    /**

 * </p>
 *
 * <p>
 * Example Usage:
 * </p>
 *
 * <pre>
 * XmlTransformer transformer = new XmlTransformer();
 * transformer.setNamespaceAware(true);
 * transformer.setCacheDuration(30);
 * transformer.addFieldRule("title", "/book/title/text()");
 * transformer.addFieldRule("author", "/book/author/name/text()");
 *
 * ResponseData responseData = new ResponseData();

                        + responseProcessor + ", url: " + url);
            }
            final Transformer transformer = ((DefaultResponseProcessor) responseProcessor).getTransformer();
            final ResultData resultData = transformer.transform(responseData);
            final Object rawData = resultData.getRawData();
            if (rawData != null) {

                if (responseProcessor instanceof DefaultResponseProcessor) {
                    final Transformer transformer = ((DefaultResponseProcessor) responseProcessor).getTransformer();
                    final ResultData resultData = transformer.transform(responseData);
                    final Object rawData = resultData.getRawData();
                    if (rawData != null) {

                .<FileTransformer> singleton("fileTransformer", FileTransformer.class, transformer -> {
                    transformer.setName("fileTransformer");
                    transformer.setFeatureMap(featureMap);
                    transformer.setPropertyMap(propertyMap);
                    transformer.setChildUrlRuleMap(childUrlRuleMap);
                })