### 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

```

            doColumn("maxAccessCount");
        }

        public void columnName() {
            doColumn("name");
        }

        public void columnNumOfThread() {
            doColumn("numOfThread");
        }

        public void columnPermissions() {
            doColumn("permissions");
        }

        public void columnSortOrder() {
            doColumn("sortOrder");
        }

                    wConfig.setMaxAccessCount(form.maxAccessCount);
                }
                wConfig.setName(configName);
                wConfig.setNumOfThread(getDefaultInteger("default.config.web.numOfThread", Constants.DEFAULT_NUM_OF_THREAD_FOR_WEB));
                wConfig.setSortOrder(getDefaultInteger("default.config.web.sortOrder", 1));
                wConfig.setUpdatedBy(username);

            result.setMaxAccessCount(DfTypeUtil.toLong(source.get("maxAccessCount")));
            result.setName(DfTypeUtil.toString(source.get("name")));
            result.setNumOfThread(DfTypeUtil.toInteger(source.get("numOfThread")));
            result.setPermissions(toStringArray(source.get("permissions")));
            result.setSortOrder(DfTypeUtil.toInteger(source.get("sortOrder")));

        assertEquals("{labels.maxAccessCount}", FessLabels.LABELS_MAX_ACCESS_COUNT);
        assertEquals("{labels.name}", FessLabels.LABELS_NAME);
        assertEquals("{labels.numOfThread}", FessLabels.LABELS_NUM_OF_THREAD);
        assertEquals("{labels.duplicateHostName}", FessLabels.LABELS_DUPLICATE_HOST_NAME);
        assertEquals("{labels.pageNumber}", FessLabels.LABELS_PAGE_NUMBER);

            result.setMaxAccessCount(DfTypeUtil.toLong(source.get("maxAccessCount")));
            result.setName(DfTypeUtil.toString(source.get("name")));
            result.setNumOfThread(DfTypeUtil.toInteger(source.get("numOfThread")));
            result.setPaths(DfTypeUtil.toString(source.get("paths")));
            result.setPermissions(toStringArray(source.get("permissions")));

    /** Indexing target identifier key. */
    public static final String INDEXING_TARGET = "indexingTarget";

    /** Number of threads configuration key. */
    public static final String NUM_OF_THREADS = "numOfThreads";

    // ============================================================
    // Authentication Type Constants
    // ============================================================

labels.includedUrls=Included URLs for Crawling
labels.includedDocPaths=Included Paths for Searching
labels.includedDocUrls=Included URLs for Searching
labels.maxAccessCount=Max Access Count
labels.name=Name
labels.numOfThread=Number of Threads
labels.duplicateHostName=Duplicate Host Name
labels.pageNumber=Page Number
labels.password=Password
labels.paths=Paths
labels.port=Port
labels.regex=Regex
labels.regularName=Regular Name

labels.includedDocPaths=Eingeschlossene Pfade für die Suche
labels.includedDocUrls=Eingeschlossene URLs für die Suche
labels.maxAccessCount=Maximale Zugriffsanzahl
labels.name=Name
labels.numOfThread=Anzahl der Threads
labels.duplicateHostName=Doppelter Hostname
labels.pageNumber=Seitennummer
labels.password=Passwort
labels.paths=Pfade
labels.port=Port
labels.regex=Regulärer Ausdruck

labels.includedDocPaths=Jalur yang Disertakan untuk Pencarian
labels.includedDocUrls=URL yang Disertakan untuk Pencarian
labels.maxAccessCount=Jumlah Akses Maksimum
labels.name=Nama
labels.numOfThread=Jumlah Thread
labels.duplicateHostName=Nama Host Duplikat
labels.pageNumber=Nomor Halaman
labels.password=Kata Sandi
labels.paths=Jalur
labels.port=Port
labels.regex=Regex
labels.regularName=Nama Reguler