An object that can create DataSources and related objects to a DataSource, like crawlers and other stuff. The Factory is one important thing in an OSGI package.

/**
 * An object that can create DataSources and related objects to a DataSource, like crawlers and other stuff. 
 * The Factory is one important thing in an OSGI package.
 * Each Factory represents one kind of DataSource object, and will only create objects regarding to this
 * kind of DataSource.
 */
public interface DataFactory {

 /**
  * get some Information that can be displayed to a user when the user wants to register new DataSources.
  * usually, you would return a label, an Icon ????, a description. etc
  * TODO: we could also split this in several methods, easier to do.
  * TODO: when we return an RDFMap, mutlilingual information is already there!!! (which may be very cool)
  */
 public Properties getInformation();
 

 /**
  * create a new, emtpy and unconfigured, DataSource instance of the DataSource class represented.
  */
 public DataSource createDataSource();

 /**
  * create a DataCrawler for this data source instance. The instance has to be configured already
  */
 public DataCrawler createDataCrawler(DataSource source);

 /**
  * create a DataAccessor for this data source instance. The instance has to be configured already,
  * and you should primarily use its getDataObject() function. The DataCrawler may use its own
  * methods to create a DataAccessor
  */
 public DataAccessor createDataAccessor(DataSource source);

 /**
  * create a HierachicalAccess for this data source instance. There are cases when no hierarchical 
  * access is supported. then, this method returns null.
  * @return a HierachicalAccess or null, when HierachicalAccess not supported by this kind of DataSource
  */
 public HierachicalAccess createHierachicalAccess(DataSource source);

  /**
  * create a DataOpener for this data source instance. There are cases when DataObjects
  * of this DataSource cannot be opened. then, this method returns null. Then you may
  * get an opener from somewhere else.
  * @return a HierachicalAccess or null, when data cannot be opened by the DAtaAccessor
  */
 public DataOpener createDataOpener(DataSource source);


}