com.solarmetric.kodo.impl.jdbc.ormapping
Class IntegerSubclassProvider

java.lang.Object
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  +--com.solarmetric.kodo.impl.jdbc.ormapping.SubclassProviderImpl
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        +--com.solarmetric.kodo.impl.jdbc.ormapping.IntegerSubclassProvider

All Implemented Interfaces:

SubclassProvider

public class IntegerSubclassProvider

extends SubclassProviderImpl

SubclassProvider implementation that uses an integer as a subclass indicator value in the database rather than the full classname. This requires that a class-to-integer mapping be specified in the metadata for the types that use this subclass provider.

These mappings are specified as demonstrated in the following example, in which rows representing com.acme.object.Foo have a value of 1 stored in the JDOCLASSX column, and rows representing com.acme.object.Bar have a value of 2:

		
			
				
				

				
				
			

			
				
				
			
		
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This class should probably be refactored to allow for easier extension for non-integer subclass indicator values. But for now, that task is left as an exercise for the reader.

Field Summary

static String

INDICATOR_VALUE The JDO metadata extension key under which the integer indicator value is stored.

Fields inherited from class com.solarmetric.kodo.impl.jdbc.ormapping.SubclassProviderImpl

CLASS_COL

Constructor Summary

IntegerSubclassProvider()

Method Summary

protected String	getClassName(Object val) Return the String name of the class corresponding to val, or null if no mapping exists for val.
protected int	getIndicatorColumnSQLType() Returns the SQLTypes type constant for the indicator column used by this mapping/provider combination.
Class	getType(PersistenceManagerImpl pm, ClassResolver resolver, Object indicatorVal) Return a Class object given that val was stored in this mapping's indicator column.
Object	getValue(PersistenceManagerImpl pm) Return an object to be stored in this mapping's indicator column.
protected void	initialize(ClassMapping cm) Ensure that an integer value is specified for this class mapping.
void	initialize(ClassMapping cm, Column[] cols) Intercept the initialization routines so we can extract a reference to the class mapping and do some validation.
void	initialize(ClassMapping cm, Table primaryTable) Intercept the initialization routines so we can extract a reference to the class mapping and do some validation.
protected void	registerSubclassMapping(Class cls, Object val) Register the mapping from cls to val.

Methods inherited from class com.solarmetric.kodo.impl.jdbc.ormapping.SubclassProviderImpl

addClassCondition, addClassCondition, addSubclassConditions, addSubclassConditions, getIndicatorColumnName, getIndicatorColumns, getSubclasses, getType, insert, select, select

Methods inherited from class java.lang.Object

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

Field Detail

INDICATOR_VALUE

public static final String INDICATOR_VALUE

The JDO metadata extension key under which the integer indicator value is stored. This has the value subclass-indicator-value.

Constructor Detail

IntegerSubclassProvider

public IntegerSubclassProvider()

Method Detail

initialize

public void initialize(ClassMapping cm,
                       Table primaryTable)

Intercept the initialization routines so we can extract a reference to the class mapping and do some validation.

Overrides:

initialize in class SubclassProviderImpl

initialize

public void initialize(ClassMapping cm,
                       Column[] cols)

Intercept the initialization routines so we can extract a reference to the class mapping and do some validation.

Overrides:

initialize in class SubclassProviderImpl

initialize

protected void initialize(ClassMapping cm)

Ensure that an integer value is specified for this class mapping. Additionally, if the class mapping represents a subclass of another persistent type, notify the superclass type's IntegerSubclassProvider of the integer mapping. This lets us lazily ensure that no two classes in the same hierarchy use the same mapping value.

getType

public Class getType(PersistenceManagerImpl pm,
                     ClassResolver resolver,
                     Object indicatorVal)

Description copied from class: SubclassProviderImpl

Return a Class object given that val was stored in this mapping's indicator column. The class should be loaded with resolver. pm is a reference to the PersistenceManagerImpl that requested that this class be loaded.

Overrides:

getType in class SubclassProviderImpl

getValue

public Object getValue(PersistenceManagerImpl pm)

Description copied from interface: SubclassProvider

Return an object to be stored in this mapping's indicator column. pm is a reference to the PersistenceManagerImpl that requested that this class be loaded.

This method should generate values from which SubclassProvider.getType(PersistenceManagerImpl,ResultSet,int,ClassResolver) can correctly determine a class.

Overrides:

getValue in class SubclassProviderImpl

getIndicatorColumnSQLType

protected int getIndicatorColumnSQLType()

Description copied from class: SubclassProviderImpl

Returns the SQLTypes type constant for the indicator column used by this mapping/provider combination.

Overrides:

getIndicatorColumnSQLType in class SubclassProviderImpl

registerSubclassMapping

protected void registerSubclassMapping(Class cls,
                                       Object val)

Register the mapping from cls to val. This ensures that no two classes in the same inheritance hierarchy have the same mapping value.

getClassName

protected String getClassName(Object val)

Return the String name of the class corresponding to val, or null if no mapping exists for val.