org.apache.cayenne.reflect

## 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 and Description
    --- | ---
    `protected ClassDescriptor` | `descriptor`
    `protected ClassDescriptorMap` | `descriptorMap`
    `protected String` | `entityName`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `LazyClassDescriptorDecorator(ClassDescriptorMap descriptorMap, String entityName)`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and 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.
    `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.
    `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.
    `ClassDescriptor` | `getSubclassDescriptor(Class<?> objectClass)` Returns the most "specialized" descriptor for a given class.
    `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` | `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()`
    `boolean` | `visitAllProperties(PropertyVisitor visitor)` Passes the visitor to the properties "visit" method for a combination of all properties, including properties declared in this descriptor, its super descriptors, and all subdescriptors.
    `boolean` | `visitDeclaredProperties(PropertyVisitor visitor)` Passes the visitor to the properties "visit" method for all properties declared in this descriptor.
    `boolean` | `visitProperties(PropertyVisitor visitor)` Passes the visitor to the properties "visit" method for all properties declared in this descriptor and all its super-decsriptors.

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### descriptor

          protected ClassDescriptor descriptor

    - #### descriptorMap

          protected ClassDescriptorMap descriptorMap

    - #### entityName

          protected String entityName

  - ### Constructor Detail

    - #### LazyClassDescriptorDecorator

          public LazyClassDescriptorDecorator(ClassDescriptorMap descriptorMap,
                                              String entityName)

  - ### Method Detail

    - #### 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`

    - #### 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.getComplimentaryReverseArc() 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(Class<?> objectClass)

      Description copied from interface: `ClassDescriptor`
      Returns the most "specialized" descriptor for a given class. This method assumes that the following is true:

           this.getObjectClass().isAssignableFrom(objectClass)

      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`

    - #### 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`

    - #### visitDeclaredProperties

          public boolean visitDeclaredProperties(PropertyVisitor visitor)

      Description copied from interface: `ClassDescriptor`
      Passes the visitor to the properties "visit" method for all properties declared in this descriptor. This property set excludes inherited properties, even those that got overridden in this subclass. Walkthrough is terminated in case one of the properties returns false. Returns true if all visited properties returned true, false - if one property returned false.
      Specified by:
        `visitDeclaredProperties` in interface `ClassDescriptor`

    - #### visitProperties

          public boolean visitProperties(PropertyVisitor visitor)

      Description copied from interface: `ClassDescriptor`
      Passes the visitor to the properties "visit" method for all properties declared in this descriptor and all its super-decsriptors. Properties that are overridden in subdescriptors will include overridden information. Walkthrough is terminated in case one of the properties returns false. Returns true if all visited properties returned true, false - if one property returned false.
      Specified by:
        `visitProperties` in interface `ClassDescriptor`

    - #### visitAllProperties

          public boolean visitAllProperties(PropertyVisitor visitor)

      Description copied from interface: `ClassDescriptor`
      Passes the visitor to the properties "visit" method for a combination of all properties, including properties declared in this descriptor, its super descriptors, and all subdescriptors. Walkthrough is terminated in case one of the properties returns false. Returns true if all visited properties returned true, false - if one property returned false.
      Specified by:
        `visitAllProperties` in interface `ClassDescriptor`

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