Version 1 (modified by dburkhar, 18 years ago) (diff)


Data Crawler

Java Interface


  • A DataCrawler accesses the physical source represented by a DataSource
  • and delivers a stream of DataObjects representing the individual items
  • in that source. */

public interface DataCrawler {


  • Constants used to indicate why a scan was stopped. */

public static enum ExitCode {

COMPLETED, the scan procedure terminated normally BY_REQUEST, the DataCrawler was requested to abort the scan procedure FATAL_EXCEPTION an error occurred that made further scanning impossible



  • Returns the DataSource crawler by this DataCrawler. */

public DataSource getDataSource();


  • Starts a scan for DataObjects over the configured domain defined
  • in the DataSource. If this is not the first run of this DataCrawler,
  • it will only report the differences with the previous run, unless the
  • previous scan results have been cleared. /

public void scan();


  • Stops a running scan operation as fast as possible. This method
  • may return before the operation has actually been stopped. /

public void stopScanning();


  • Clears all stored scan results. Any listeners registered with
  • this data source will be notified of the removal of the data
  • objects. The next call to scan() will again report all
  • data objects in the configured domain. /

public void clearScanResults();


  • Gets the ScanReport of the last performed scan, or the current
  • scan when a scan is in progress. Returns null when
  • no scan was performed in this session and there is no scan report
  • available from the previous session.
  • @return The ScanReport of the last session, or null when
  • this is not available. /

public ScanReport getLastScanReport();


  • Adds a DataSourceListener to which this data source should
  • report any scanned or cleared data objects. *
  • @param listener The DataCrawlerListener to add. /

public void addListener(DataCrawlerListener listener);


  • Removes a DataSourceListener from this data source. *
  • @param listener The DataCrawlerListener to remove. /

public void removeListener(DataCrawlerListener listener);