com.aspc.DBObj.Internal

Class LookupOutwardLink

java.lang.Object

com.aspc.DBObj.Internal.Link

com.aspc.DBObj.Internal.OutwardLink

com.aspc.DBObj.Internal.LookupOutwardLink

public class LookupOutwardLink
extends OutwardLink

LookupOutwardLink Used in imports where a single set of values needs to update several objects and maintain there relationship to each other. As in the Path class this class will return the next object in the path in the nextStep method. e.g. Person:date - would simply return the base object supplied which should be based on the class Person Person:companyId - would actually return the company object linked to the base object The difference with the LookupOutwardLink is that it will always return a linked object which will match a series of field values that is supplied. If no lookup fields are provided then this method will return the target based on the standard OutwardLink nextStep method. For the companyId example, if a lookup was supplied of company.name = "ASPConverters" the following would occur 1. (Check Link) - the linked company would be retrieved as normal. If it did not have a name of "ASPConverters" then the link would be cleared and we would go onto the second step. If it did match then we would simply return the company 2. (Find link) - we would search for a company with the name of "ASPConverters". If one was found then we would use this company and link the persons company id to this company. If more then one company is found then a TooManyRows exception is thrown. 3. (Create link) - If no match is found then we would create a new company. We would set the company's name to "ASPConverters" so that we would have a valid match. We would use this company and link the persons company id to this company. THREAD MODE: MULTI-THREADED shared but non-mutable

Since:

March 22, 2001, 1:49 PM

Author:

Jason McGrath

Field Summary

Fields inherited from class com.aspc.DBObj.Internal.Link

baseClass, baseField

Constructor Summary

Constructors

Constructor and Description
LookupOutwardLink(java.lang.String thePath, VirtualDB layer, DBClassConcrete baseClass)

Method Summary

Modifier and Type	Method and Description
void	addLookup(DBField fld, java.lang.Object value) Sets a value for a field that can be used for looking up linked objects.
protected DBObject	createTarget(DBObject base)
DBObject	nextStep(DBObject base, boolean createMissingObjects, HintField hint) The next step in the path

Methods inherited from class com.aspc.DBObj.Internal.OutwardLink

equals, getAsciiDescription, getAsciiDescription, getBinaryDescription, getBinaryDescription, getParams, nextStepClassConcrete, toString

Methods inherited from class com.aspc.DBObj.Internal.Link

compatibleClass, createLink, findBaseField, getBaseClassConcrete, getBaseField

Methods inherited from class java.lang.Object

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

Constructor Detail

LookupOutwardLink

public LookupOutwardLink(java.lang.String thePath,
                         VirtualDB layer,
                         DBClassConcrete baseClass)
                  throws InvalidLink

Parameters:

thePath -

layer - the layer

baseClass - The base class

Throws:

InvalidLink

Method Detail

nextStep

@CheckReturnValue
 @Nullable
public DBObject nextStep(DBObject base,
                                                      boolean createMissingObjects,
                                                      HintField hint)
                                               throws java.lang.Exception

Description copied from class: OutwardLink

The next step in the path

Overrides:

nextStep in class OutwardLink

Parameters:

base - the base object

createMissingObjects -

hint - the hint

Returns:

the value

Throws:

java.lang.Exception - a serious problem

addLookup

public void addLookup(DBField fld,
                      java.lang.Object value)

Sets a value for a field that can be used for looking up linked objects.

Parameters:

fld -

value - the value

createTarget

protected DBObject createTarget(DBObject base)
                         throws java.lang.Exception

Parameters:

base - the base object

Returns:

the value

Throws:

java.lang.Exception - a serious problem