/**
     * Reference to the parent thread that started the crawler.
     */
    protected Thread parentThread;

    /**
     * The thread group for crawler threads.
     */
    protected ThreadGroup crawlerThreadGroup;

    /**
     * Constructs a new Crawler instance.
     * Initializes the crawler context with a new session ID based on the current timestamp.
     */
    public Crawler() {

     * Field name for method.
     */
    public static final String METHOD = "method";

    /**
     * Field name for URL.
     */
    public static final String URL = "url";

    /**
     * Field name for parent URL.
     */
    public static final String PARENT_URL = "parentUrl";

    /**
     * Field name for depth.
     */
    public static final String DEPTH = "depth";

    /**

        int count = 0;
        int prev = -1;
        Map<String, Object> source;
        while ((source = reader.read()) != null) {
            int current = Integer.parseInt(source.get("field2").toString());
            assertTrue(prev < current);
            prev = current;
            count++;
        }
        assertEquals(num, count);

        reader = new ESSourceReader(client, settings, indexName);

		<url>******@****.***:codelibs/fess-crawler.git</url>
	  <tag>HEAD</tag>
  </scm>
	<parent>
		<groupId>org.codelibs.fess</groupId>
		<artifactId>fess-parent</artifactId>
		<version>15.3.0-SNAPSHOT</version>
	</parent>
	<modules>
		<module>fess-crawler</module>
		<module>fess-crawler-lasta</module>
		<module>fess-crawler-opensearch</module>
	</modules>
	<build>

    public void close() throws IOException {
        try {
            fileInputStream.close();
        } finally {
            FileUtil.deleteInBackground(tempFile);
        }
    }

    /**
     * Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.
     * This method delegates to {@link FileInputStream#mark(int)}.

	<packaging>jar</packaging>
	<name>Fess Crawler for LastaFlute</name>
	<description>This is LastaFlute support.</description>
	<parent>
		<groupId>org.codelibs.fess</groupId>
		<artifactId>fess-crawler-parent</artifactId>
		<version>15.3.0-SNAPSHOT</version>
		<relativePath>../pom.xml</relativePath>
	</parent>
	<build>
		<plugins>
			<plugin>
				<artifactId>maven-compiler-plugin</artifactId>
			</plugin>
			<plugin>

	<artifactId>fess-crawler-opensearch</artifactId>
	<packaging>jar</packaging>
	<name>Fess Crawler OpenSearch</name>
	<parent>
		<groupId>org.codelibs.fess</groupId>
		<artifactId>fess-crawler-parent</artifactId>
		<version>15.3.0-SNAPSHOT</version>
		<relativePath>../pom.xml</relativePath>
	</parent>
	<build>
		<plugins>
			<plugin>
				<artifactId>maven-compiler-plugin</artifactId>
			</plugin>
			<plugin>

		<url>https://github.com/codelibs/fess-suggest</url>
	  <tag>HEAD</tag>
  </scm>
	<parent>
		<groupId>org.codelibs.fess</groupId>
		<artifactId>fess-parent</artifactId>
		<version>15.3.0-SNAPSHOT</version>
		<relativePath />
	</parent>
	<build>
		<plugins>
			<plugin>
				<artifactId>maven-compiler-plugin</artifactId>
			</plugin>
			<plugin>

            throw new CrawlerSystemException("CrawlerClient is null.");
        }
        int current = 0;
        boolean added = false;
        final Map<Pattern, CrawlerClient> newClientMap = new LinkedHashMap<>();
        for (final Map.Entry<Pattern, CrawlerClient> entry : clientMap.entrySet()) {
            if (pos == current) {
                newClientMap.put(Pattern.compile(regex), client);
                added = true;

    }

    /**
     * Gets the parent URL from which this resource was discovered.
     *
     * @return the parent URL, or null if this is a root URL
     */
    public String getParentUrl() {
        return parentUrl;
    }

    /**
     * Sets the parent URL from which this resource was discovered.
     *
     * @param parentUrl the parent URL to set
     */