All Packages  Class Hierarchy  This Package  Previous  Next  Index

Interface de.tudarmstadt.ito.xmldbms.KeyGenerator

public interface KeyGenerator
Interface for a class that generates key values (object IDs).

Applications that want DOMToDBMS to generate key values pass an instance of an object that implements this class to DOMToDBMS. Keys are used to join tables (class table-to-class table or class table- to-property table) and also to retrieve data from root tables. Whether DOMToDBMS generates a key for a given table (or one or more properties are mapped to the key columns) depends on the mapping to that table.

Programmers using XML-DBMS never need to call the method (generateKey) in this interface; it is called only by DOMToDBMS. Programmers only need to supply an object that implements this interface to DOMToDBMS if they want DOMToDBMS to generate keys.

The helper class KeyGeneratorImpl provides a default implementation of this interface.

Ronald Bourret, Technical University of Darmstadt
See Also:

Method Index

 o generateKey()
Generates a key.


 o generateKey
 public abstract Object[] generateKey() throws KeyException
Generates a key.

This method is called by DOMToDBMS. Programmers using DOMToDBMS do not need to call this method.

The key as an array of Objects.
Throws: KeyException
An error occured while generating the key.

All Packages  Class Hierarchy  This Package  Previous  Next  Index