* @return The maximum depth.
     */
    public int getMaxDepth() {
        return maxDepth;
    }

    /**
     * Sets the maximum depth.
     * @param maxDepth The maximum depth.
     */
    public void setMaxDepth(final int maxDepth) {
        this.maxDepth = maxDepth;
    }

    /**
     * Returns the maximum access count.
     * @return The maximum access count.

        if (dataMap.remove(getParamValue(paramMap, "field.max_depth", "max_depth")) instanceof final String maxDepth
                && StringUtil.isNotBlank(maxDepth)) {
            try {
                return Integer.parseInt(maxDepth);
            } catch (final NumberFormatException e) {
                if (logger.isDebugEnabled()) {
                    logger.warn("Failed to parse max_depth: '{}'. Expected: integer value", maxDepth, e);

        crawlerContext.maxThreadCheckCount = maxThreadCheckCount;
    }

    /**
     * Sets the maximum depth.
     * @param maxDepth The maximum depth.
     */
    public void setMaxDepth(final int maxDepth) {
        crawlerContext.maxDepth = maxDepth;
    }

    /**
     * Sets the maximum access count.
     * @param maxAccessCount The maximum access count.
     */

### Core Classes

- **Crawler** (`Crawler.java`): Main orchestrator - `execute()`, `addUrl()`, `cleanup()`, `stop()`
- **CrawlerContext** (`CrawlerContext.java`): Execution context - `sessionId`, `status`, `accessCount`, `numOfThread`, `maxDepth`, `maxAccessCount`
- **CrawlerThread** (`CrawlerThread.java`): Worker thread - Poll URL → Validate → Execute → Process → Queue children

### HTTP Client Architecture

```

	<component name="filenameExtractor"
		class="org.codelibs.fess.crawler.extractor.impl.FilenameExtractor" />
	<component name="jsonExtractor"
		class="org.codelibs.fess.crawler.extractor.impl.JsonExtractor">
		<property name="maxDepth">10</property>
		<property name="extractMetadata">true</property>
	</component>
	<component name="csvExtractor"
		class="org.codelibs.fess.crawler.extractor.impl.CsvExtractor">
		<property name="hasHeader">true</property>