| 1 | {{{ |
| 2 | #!java |
| 3 | /** |
| 4 | * A general interface for folder data objects. |
| 5 | * Folders are important for structured datasources. They will also contain all the links |
| 6 | * from the folder to its containing children (using the appropriate relating property) in |
| 7 | * its getMetadata() RDF Map. So you can get the identifiers of children either using hte |
| 8 | * getChildren() method or via getMetadata() where all the children are also listed. |
| 9 | * Listing the relations between folders and their children is very useful for large |
| 10 | * search databases, that can make use of the semantic structure. |
| 11 | * |
| 12 | */ |
| 13 | public interface DataObjectFolder { |
| 14 | |
| 15 | |
| 16 | /** |
| 17 | * Gets the data object's parent, if any. |
| 18 | * |
| 19 | * @return the parent DataObject, or null when this DataObject has no parent. |
| 20 | */ |
| 21 | public DataObject getParent(); |
| 22 | |
| 23 | /** |
| 24 | * Gets the data object's children, if any. This may be null to indicate that there |
| 25 | * are no children. |
| 26 | * @return an Iterator over DataObject objects |
| 27 | */ |
| 28 | public Iterator getChildren(); |
| 29 | |
| 30 | |
| 31 | /** |
| 32 | * Get the source-specific metadata and data. |
| 33 | * The used keys and values and implementation-dependent. |
| 34 | * For java1.4 compability reasons, the map is untyped. |
| 35 | * It is already titled RDFMap to reflect our ideas regarding RDF |
| 36 | * |
| 37 | * @return The scheme-specific metadata. |
| 38 | */ |
| 39 | public RDFMap getMetadata(); |
| 40 | |
| 41 | } |
| 42 | }}} |