org.apache.ojb.broker.accesslayer
Class BasePrefetcher

java.lang.Object
  org.apache.ojb.broker.accesslayer.BasePrefetcher

All Implemented Interfaces:

RelationshipPrefetcher

Direct Known Subclasses:

PlainPrefetcher, RelationshipPrefetcherImpl

public abstract class BasePrefetcher
extends Object
implements RelationshipPrefetcher

Abstract Prefetcher.

Version:

$Id: BasePrefetcher.java,v 1.1 2007-08-24 22:17:30 ewestfal Exp $

Author:

Oleg Nitz

Field Summary

protected static int	IN_LIMIT The numer of columns to query for.
protected ClassDescriptor	itemClassDesc Class descriptor for the item type.
protected int	pkLimit Maximum number of pk's in one query.

Constructor Summary

BasePrefetcher(PersistenceBrokerImpl aBroker, Class anItemClass)
Constructor for BasePrefetcher.

Method Summary

protected abstract void	associateBatched(Collection owners, Collection children) associate the batched Children with their owner object
protected Criteria	buildPrefetchCriteria(Collection ids, FieldDescriptor[] fields)
protected abstract Query[]	buildPrefetchQueries(Collection owners, Collection children)
protected QueryByCriteria	buildPrefetchQuery(Class clazz, Collection ids, FieldDescriptor[] fields)
protected QueryByCriteria	buildPrefetchQuery(Collection ids, FieldDescriptor[] fields)
protected PersistenceBrokerImpl	getBroker() Returns the broker.
protected DescriptorRepository	getDescriptorRepository() Return the DescriptorRepository
ClassDescriptor	getItemClassDescriptor() Returns the ClassDescriptor of the item Class
int	getLimit() The limit of objects loaded by one SQL query
protected Logger	getLogger() Returns the logger.
void	prefetchRelationship(Collection owners) Prefetch the Relationship for the owners (the 1 side of a 1:n)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.ojb.broker.accesslayer.RelationshipPrefetcher

prepareRelationshipSettings, restoreRelationshipSettings

Field Detail

IN_LIMIT

protected static final int IN_LIMIT

The numer of columns to query for.

itemClassDesc

protected ClassDescriptor itemClassDesc

Class descriptor for the item type.

pkLimit

protected final int pkLimit

Maximum number of pk's in one query.

Constructor Detail

BasePrefetcher

public BasePrefetcher(PersistenceBrokerImpl aBroker,
                      Class anItemClass)

Constructor for BasePrefetcher.

Method Detail

getLimit

public int getLimit()

The limit of objects loaded by one SQL query

Specified by:

getLimit in interface RelationshipPrefetcher

associateBatched

protected abstract void associateBatched(Collection owners,
                                         Collection children)

associate the batched Children with their owner object

prefetchRelationship

public void prefetchRelationship(Collection owners)

Description copied from interface: RelationshipPrefetcher

Prefetch the Relationship for the owners (the 1 side of a 1:n)

Specified by:

prefetchRelationship in interface RelationshipPrefetcher

See Also:

RelationshipPrefetcher.prefetchRelationship(Collection)

buildPrefetchQuery

protected QueryByCriteria buildPrefetchQuery(Collection ids,
                                             FieldDescriptor[] fields)

buildPrefetchCriteria

protected Criteria buildPrefetchCriteria(Collection ids,
                                         FieldDescriptor[] fields)

Parameters:

ids - collection of identities

fields -

Returns:

buildPrefetchQuery

protected QueryByCriteria buildPrefetchQuery(Class clazz,
                                             Collection ids,
                                             FieldDescriptor[] fields)

Parameters:

clazz -

ids - collection of identities

fields -

Returns:

getDescriptorRepository

protected DescriptorRepository getDescriptorRepository()

Return the DescriptorRepository

getItemClassDescriptor

public ClassDescriptor getItemClassDescriptor()

Returns the ClassDescriptor of the item Class

Specified by:

getItemClassDescriptor in interface RelationshipPrefetcher

Returns:

ClassDescriptor

buildPrefetchQueries

protected abstract Query[] buildPrefetchQueries(Collection owners,
                                                Collection children)

getBroker

protected PersistenceBrokerImpl getBroker()

Returns the broker.

Returns:

PersistenceBrokerImpl

getLogger

protected Logger getLogger()

Returns the logger.

Returns:

Logger