ome.services.query

Class HierarchyNavigator

java.lang.Object

ome.services.query.HierarchyNavigator

Direct Known Subclasses:

HierarchyNavigatorWrap

public class HierarchyNavigator
extends Object

Query the database for relationships between model objects. Caches results, so designed for a short lifetime.

Since:

5.0

Author:

m.t.b.carroll@dundee.ac.uk

Field Summary

Fields

Modifier and Type	Field and Description
protected IQuery	iQuery available query service

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	HierarchyNavigator(IQuery iQuery) Construct a new hierarchy navigator.

Method Summary

Methods

Modifier and Type	Method and Description
protected com.google.common.collect.ImmutableSet<Long>	doLookup(String toType, String fromType, Long fromId) Look up which objects of a given type relate to the given query object.
protected void	prepareLookups(String toType, String fromType, Collection<Long> fromIds) Batch bulk database queries to prime the cache for doLookup(String, String, Long).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

iQuery

protected final IQuery iQuery

available query service

Constructor Detail

HierarchyNavigator

protected HierarchyNavigator(IQuery iQuery)

Construct a new hierarchy navigator.

Parameters:

iQuery - the query service

Method Detail

prepareLookups

protected void prepareLookups(String toType,
                  String fromType,
                  Collection<Long> fromIds)

Batch bulk database queries to prime the cache for doLookup(String, String, Long). It is not necessary to call this method, but it is advised if many lookups are anticipated.

Parameters:

toType - the type of the objects to which the query objects may be related, not null

fromType - the query object's type, not null

fromIds - the query objects' database IDs, none null

doLookup

protected com.google.common.collect.ImmutableSet<Long> doLookup(String toType,
                                                    String fromType,
                                                    Long fromId)

Look up which objects of a given type relate to the given query object. Caches results, and one may bulk-cache results in advance using prepareLookups(String, String, Collection).

Parameters:

toType - the type of the objects to which the query object may be related, not null

fromType - the query object's type, not null

fromIds - the query object's database ID, not null

Returns:

the related objects' database IDs, never null