Class LazyClassDescriptorDecorator

java.lang.Object

org.apache.cayenne.reflect.LazyClassDescriptorDecorator

All Implemented Interfaces:

ClassDescriptor

public class LazyClassDescriptorDecorator
extends Object
implements ClassDescriptor

A ClassDescriptor wrapper that compiles decorated descriptor lazily on first access.

Since:

3.0

Field Summary

Fields

Modifier and Type	Field	Description
protected ClassDescriptor	descriptor
protected ClassDescriptorMap	descriptorMap
protected String	entityName

Constructor Summary

Constructors

Constructor	Description
LazyClassDescriptorDecorator(ClassDescriptorMap descriptorMap, String entityName)

Method Summary

Modifier and Type	Method	Description
protected void	checkDescriptorInitialized()	Checks whether decorated descriptor is initialized, and if not, creates it using parent ClassDescriptorMap.
Object	createObject()	Creates a new instance of a class described by this object.
Map<CayennePath, AdditionalDbEntityDescriptor>	getAdditionalDbEntities()	Returns information about additional db entities that is used for this ObjEntity (i.e. for flattened attributes).
Collection<PropertyDescriptor>	getAllProperties()	Returns a combination of all properties, including properties declared in this descriptor, its super descriptors, and all subdescriptors.
Collection<PropertyDescriptor>	getDeclaredProperties()	Returns the properties declared in this descriptor.
PropertyDescriptor	getDeclaredProperty(String propertyName)	Returns a Java Bean property descriptor matching property name or null if no such property is found.
ClassDescriptor	getDescriptor()	Returns underlying descriptor used to delegate all processing, resolving it if needed.
Collection<ObjAttribute>	getDiscriminatorColumns()	Returns a collection of ObjAttribute for the described class, its superclasses and subclasses, that participate in inheritance qualifier.
ObjEntity	getEntity()	Returns an ObjEntity associated with this descriptor.
EntityInheritanceTree	getEntityInheritanceTree()
Expression	getEntityQualifier()	Returns entity qualifier as a Cayenne expression that includes qualifiers for this entity and all subentities.
Collection<AttributeProperty>	getIdProperties()	Returns a collection of the properties mapped to id columns.
Collection<ArcProperty>	getMapArcProperties()	Returns a collection over the arc properties whose reverse arcs are to-many maps.
Class<?>	getObjectClass()	Returns a class mapped by this descriptor.
Collection<PropertyDescriptor>	getProperties()	Returns the properties declared in this descriptor and all its super-descriptors.
PropertyDescriptor	getProperty(String propertyName)	Returns a property descriptor matching property name, or null if no such property is found.
Collection<DbEntity>	getRootDbEntities()	Returns a collection of DbEntities that are the root tables for this descriptor's ObjEntity.
DataRowLayout	getSnapshotLayout()	Returns the layout of a snapshot of an object of the described class: the columns of the attributes, the foreign keys of the to-one relationships whose targets propagate their keys to this entity, the primary key, and the primary keys of the additional DB entities, each column listed once.
ClassDescriptor	getSubclassDescriptor(String entityName)	Returns the most "specialized" descriptor for a given entity name.
ClassDescriptor	getSuperclassDescriptor()	Returns a descriptor of the mapped superclass or null if the descriptor's entity sits at the top of inheritance hierarchy or no inheritance is mapped.
boolean	hasSubclasses()	Returns whether this class has persistent subclasses.
void	injectDiscriminatorValues(Object object)	Sets the attribute values that the entity qualifier implies for a new object of the described class, such as the discriminator of a single-table inheritance subentity.
void	injectValueHolders(Object object)	Prepares object properties for access.
boolean	isFault(Object object)	Returns true if an object is not fully resolved.
void	shallowMerge(Object from, Object to)	Merges object properties from one object to another, avoiding traversal of the ArcProperties.
String	toString()

Methods inherited from class Object

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

Methods inherited from interface ClassDescriptor

getSubclassDescriptor, visitAllProperties, visitDeclaredProperties, visitProperties

Field Details

descriptor

protected ClassDescriptor descriptor

descriptorMap

protected ClassDescriptorMap descriptorMap

entityName

protected String entityName

Constructor Details

LazyClassDescriptorDecorator

public LazyClassDescriptorDecorator(ClassDescriptorMap descriptorMap,
 String entityName)

Method Details

toString

public String toString()

Overrides:

toString in class Object

checkDescriptorInitialized

protected void checkDescriptorInitialized()

Checks whether decorated descriptor is initialized, and if not, creates it using parent ClassDescriptorMap.

getDescriptor

public ClassDescriptor getDescriptor()

Returns underlying descriptor used to delegate all processing, resolving it if needed.

createObject

public Object createObject()

Description copied from interface: ClassDescriptor

Creates a new instance of a class described by this object.

Specified by:

createObject in interface ClassDescriptor

getDeclaredProperty

public PropertyDescriptor getDeclaredProperty(String propertyName)

Description copied from interface: ClassDescriptor

Returns a Java Bean property descriptor matching property name or null if no such property is found. Lookup DOES NOT including properties from the superclass descriptors. Returned property can be any one of AttributeProperty, ToManyProperty, ToOneProperty.

Specified by:

getDeclaredProperty in interface ClassDescriptor

getEntity

public ObjEntity getEntity()

Description copied from interface: ClassDescriptor

Returns an ObjEntity associated with this descriptor.

Specified by:

getEntity in interface ClassDescriptor

getRootDbEntities

public Collection<DbEntity> getRootDbEntities()

Description copied from interface: ClassDescriptor

Returns a collection of DbEntities that are the root tables for this descriptor's ObjEntity. Usually such collection would contain only one entity, however in cases involving subclass horizontal inheritance, it will be more than one, and in cases of abstract entities with no subclasses, the collection will be empty.

Specified by:

getRootDbEntities in interface ClassDescriptor

getAdditionalDbEntities

public Map<CayennePath, AdditionalDbEntityDescriptor> getAdditionalDbEntities()

Description copied from interface: ClassDescriptor

Returns information about additional db entities that is used for this ObjEntity (i.e. for flattened attributes).

Keys are full paths for corresponding flattened attributes.

Specified by:

getAdditionalDbEntities in interface ClassDescriptor

Returns:

information about additional db entities

getEntityInheritanceTree

public EntityInheritanceTree getEntityInheritanceTree()

Specified by:

getEntityInheritanceTree in interface ClassDescriptor

hasSubclasses

public boolean hasSubclasses()

Description copied from interface: ClassDescriptor

Returns whether this class has persistent subclasses.

Specified by:

hasSubclasses in interface ClassDescriptor

getObjectClass

public Class<?> getObjectClass()

Description copied from interface: ClassDescriptor

Returns a class mapped by this descriptor.

Specified by:

getObjectClass in interface ClassDescriptor

getIdProperties

public Collection<AttributeProperty> getIdProperties()

Description copied from interface: ClassDescriptor

Returns a collection of the properties mapped to id columns.

Specified by:

getIdProperties in interface ClassDescriptor

getDiscriminatorColumns

public Collection<ObjAttribute> getDiscriminatorColumns()

Description copied from interface: ClassDescriptor

Returns a collection of ObjAttribute for the described class, its superclasses and subclasses, that participate in inheritance qualifier. If a discriminator expression specifies a DbAttribute instead of an ObjAttribute, a synthetic ObjAttribute is created and returned.

Specified by:

getDiscriminatorColumns in interface ClassDescriptor

getEntityQualifier

public Expression getEntityQualifier()

Description copied from interface: ClassDescriptor

Returns entity qualifier as a Cayenne expression that includes qualifiers for this entity and all subentities.

Specified by:

getEntityQualifier in interface ClassDescriptor

getMapArcProperties

public Collection<ArcProperty> getMapArcProperties()

Description copied from interface: ClassDescriptor

Returns a collection over the arc properties whose reverse arcs are to-many maps. I.e. for each ArcProperty in returned collection, the following is true:

arc.getComplementaryReverseArc() instanceof ToManyMapProperty

Specified by:

getMapArcProperties in interface ClassDescriptor

getProperty

public PropertyDescriptor getProperty(String propertyName)

Description copied from interface: ClassDescriptor

Returns a property descriptor matching property name, or null if no such property is found. Lookup includes properties from this descriptor and all its superclass descriptors. Returned property can be any one of AttributeProperty, ToManyProperty, ToOneProperty.

Specified by:

getProperty in interface ClassDescriptor

getSubclassDescriptor

public ClassDescriptor getSubclassDescriptor(String entityName)

Description copied from interface: ClassDescriptor

Returns the most "specialized" descriptor for a given entity name.

Specified by:

getSubclassDescriptor in interface ClassDescriptor

getSuperclassDescriptor

public ClassDescriptor getSuperclassDescriptor()

Description copied from interface: ClassDescriptor

Returns a descriptor of the mapped superclass or null if the descriptor's entity sits at the top of inheritance hierarchy or no inheritance is mapped.

Specified by:

getSuperclassDescriptor in interface ClassDescriptor

injectValueHolders

public void injectValueHolders(Object object)
                        throws PropertyException

Description copied from interface: ClassDescriptor

Prepares object properties for access. This may include injection of value holders into the object and such.

Specified by:

injectValueHolders in interface ClassDescriptor

Throws:

PropertyException

injectDiscriminatorValues

public void injectDiscriminatorValues(Object object)
                               throws PropertyException

Description copied from interface: ClassDescriptor

Sets the attribute values that the entity qualifier implies for a new object of the described class, such as the discriminator of a single-table inheritance subentity. Only the qualifier declared on the entity itself is used, as in query translation, where entity qualifiers are not combined with those of the super entities.

Specified by:

injectDiscriminatorValues in interface ClassDescriptor

Throws:

PropertyException

isFault

public boolean isFault(Object object)

Description copied from interface: ClassDescriptor

Returns true if an object is not fully resolved.

Specified by:

isFault in interface ClassDescriptor

shallowMerge

public void shallowMerge(Object from,
 Object to)
                  throws PropertyException

Description copied from interface: ClassDescriptor

Merges object properties from one object to another, avoiding traversal of the ArcProperties.

Specified by:

shallowMerge in interface ClassDescriptor

Throws:

PropertyException

getProperties

public Collection<PropertyDescriptor> getProperties()

Description copied from interface: ClassDescriptor

Returns the properties declared in this descriptor and all its super-descriptors. Properties that are overridden in subdescriptors include the overridden information. Each property is one of AttributeProperty, ToOneProperty, ToManyProperty. The returned collection must not be modified.

Specified by:

getProperties in interface ClassDescriptor

getDeclaredProperties

public Collection<PropertyDescriptor> getDeclaredProperties()

Description copied from interface: ClassDescriptor

Returns the properties declared in this descriptor. This property set excludes inherited properties, even those that got overridden in this subclass. Each property is one of AttributeProperty, ToOneProperty, ToManyProperty. The returned collection must not be modified.

Specified by:

getDeclaredProperties in interface ClassDescriptor

getAllProperties

public Collection<PropertyDescriptor> getAllProperties()

Description copied from interface: ClassDescriptor

Returns a combination of all properties, including properties declared in this descriptor, its super descriptors, and all subdescriptors. Each property is one of AttributeProperty, ToOneProperty, ToManyProperty. The returned collection must not be modified.

Specified by:

getAllProperties in interface ClassDescriptor

getSnapshotLayout

public DataRowLayout getSnapshotLayout()

Description copied from interface: ClassDescriptor

Returns the layout of a snapshot of an object of the described class: the columns of the attributes, the foreign keys of the to-one relationships whose targets propagate their keys to this entity, the primary key, and the primary keys of the additional DB entities, each column listed once. Snapshots of objects are built over this layout, and rows of any layout are merged into objects through it.

Specified by:

getSnapshotLayout in interface ClassDescriptor