org.kuali.ole.fp.dataaccess

Class PolymorphicMultiColumnDiscriminator

java.lang.Object

org.apache.ojb.broker.accesslayer.RowReaderDefaultImpl

org.kuali.ole.fp.dataaccess.PolymorphicMultiColumnDiscriminator

All Implemented Interfaces:

Serializable, org.apache.ojb.broker.accesslayer.RowReader

public abstract class PolymorphicMultiColumnDiscriminator
extends org.apache.ojb.broker.accesslayer.RowReaderDefaultImpl

(Inspired by example posted at http://nagoya.apache.org/eyebrowse/ReadMsg?listName=ojb-user@db.apache.org&msgId=749837) This class enables mapping multiple (presumably similar) classes to a single database table. Subclasses must implement the getDiscriminatorColumns method, returning a String array of columns to consider when determining which class to return, as well as implement the corresponding chooseClass method that acts on received values for those columns. Sample OBJ config: ... ... (where ClassADiscriminator and ClassBDiscriminator extend PolymorphicMultiColumnDiscriminator)

See Also:

Serialized Form

Field Summary

Fields inherited from interface org.apache.ojb.broker.accesslayer.RowReader

serialVersionUID

Constructor Summary

Constructors

Constructor and Description
PolymorphicMultiColumnDiscriminator(org.apache.ojb.broker.metadata.ClassDescriptor cld)

Method Summary

Methods

Modifier and Type	Method and Description
abstract Class	chooseClass(String[] values) Based on the received key values, this method determines the appropriate class.
abstract String[]	getDiscriminatorColumns() This method should return the column(s) necessary to determine which class to cast to.
protected org.apache.ojb.broker.metadata.ClassDescriptor	selectClassDescriptor(Map row)

Methods inherited from class org.apache.ojb.broker.accesslayer.RowReaderDefaultImpl

buildOrRefreshObject, extractOjbConcreteClass, getClassDescriptor, readObjectArrayFrom, readObjectFrom, readPkValuesFrom, readValuesFrom, refreshObject, setClassDescriptor

Methods inherited from class java.lang.Object

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

Constructor Detail

PolymorphicMultiColumnDiscriminator

public PolymorphicMultiColumnDiscriminator(org.apache.ojb.broker.metadata.ClassDescriptor cld)

Method Detail

getDiscriminatorColumns

public abstract String[] getDiscriminatorColumns()

This method should return the column(s) necessary to determine which class to cast to.

Returns:

one or more column names

chooseClass

public abstract Class chooseClass(String[] values)

Based on the received key values, this method determines the appropriate class.

Parameters:

values -

Returns:

an appropriately chosen class

selectClassDescriptor

protected org.apache.ojb.broker.metadata.ClassDescriptor selectClassDescriptor(Map row)
                                                                        throws org.apache.ojb.broker.PersistenceBrokerException

Overrides:

selectClassDescriptor in class org.apache.ojb.broker.accesslayer.RowReaderDefaultImpl

Throws:

org.apache.ojb.broker.PersistenceBrokerException