com.lightdev.tree.data
Interface HierarchicalDataStore

public interface HierarchicalDataStore

HierarchicalDataStore.java

Classes wishing to persistently store or load hierarchical data need to implement this interface. It is assumed that hierarchical data items, i.e. items that are linked with a 1:n parent-child relation, are identified each with a unique id.

Version:

2, 30.03.2006

Author:

Ulrich Hilger, Light Development, http://www.lightdev.com, info@lightdev.com, published under the terms and conditions of the BSD License, for details see file license.txt in the distribution package of this software

Method Summary

Object	createItem(HierarchicalItem item) create a new item in the data store
Object	deleteItem(Object id) delete the item with the given id from the data store
Vector<HierarchicalItem>	getChildItems(Object id) get all child items of a given item
HierarchicalItem	getItem(Object id) get the item with the given id
Vector<HierarchicalItem>	getRootItems() get all root items in the data store, i.e. all top level items in the item hierarchy that have no parent
HierarchicalItem	putItem(HierarchicalItem item) store an item with the given id

Method Detail

getItem

HierarchicalItem getItem(Object id)

                         throws StorageException

get the item with the given id

Parameters:

id - the id of the item to get

Returns:

the item with the given id or null, if none was found with that id

Throws:

StorageException

getChildItems

Vector<HierarchicalItem> getChildItems(Object id)

                                       throws StorageException

get all child items of a given item

Parameters:

id - the id of the item to get child items for

Returns:

a Vector of HierarchicalItem objects or null if an item with the given id was not found

Throws:

StorageException

getRootItems

Vector<HierarchicalItem> getRootItems()

                                      throws StorageException

get all root items in the data store, i.e. all top level items in the item hierarchy that have no parent

Returns:

a Vector of HierarchicalItems with all root items

Throws:

StorageException

putItem

HierarchicalItem putItem(HierarchicalItem item)

                         throws StorageException

store an item with the given id

Parameters:

item - the item to store

Returns:

the item that has been stored or null if no item with that id was found

Throws:

StorageException

createItem

Object createItem(HierarchicalItem item)

                  throws StorageException

create a new item in the data store

Parameters:

item - the new item to create

Returns:

the id of the newly create item

Throws:

StorageException

deleteItem

Object deleteItem(Object id)

                  throws StorageException

delete the item with the given id from the data store

Parameters:

id -

Returns:

the id of the deleted item or null if an item with the given id was not found

Throws:

StorageException