Package org.exolab.castor.mapping

Class GeneralizedFieldHandler

java.lang.Object
org.exolab.castor.mapping.loader.FieldHandlerFriend
org.exolab.castor.mapping.ExtendedFieldHandler
org.exolab.castor.mapping.AbstractFieldHandler
org.exolab.castor.mapping.GeneralizedFieldHandler
All Implemented Interfaces:
ConfigurableFieldHandler, FieldHandler
Direct Known Subclasses:
EnumFieldHandler, SQLTimeFieldHandler, SQLTimestampFieldHandler, ToStringFieldHandler, ValueOfFieldHandler
public abstract class GeneralizedFieldHandler extends AbstractFieldHandler
An extended version of the FieldHandler interface which is used for making generic libraries of FieldHandlers which can be used for more than one field or class, but have similar conversion algorithms.
Version:
$Revision: 6216 $ $Date: 2005-01-18 17:29:45 -0700 (Tue, 18 Jan 2005) $
Author:
Keith Visco
See Also:

  • Constructor Details

    • GeneralizedFieldHandler

      protected GeneralizedFieldHandler()
      Creates a new default GeneralizedFieldHandler. This method should be called by all extending classes so that any important initialization code will be executed.

  • Method Details

    • convertUponGet

      public abstract Object convertUponGet(Object value)
      This method is used to convert the value when the getValue method is called. The getValue method will obtain the actual field value from given 'parent' object. This convert method is then invoked with the field's value. The value returned from this method will be the actual value returned by getValue method.
      Parameters:
      value - the object value to convert after performing a get operation
      Returns:
      the converted value.

    • convertUponSet

      public abstract Object convertUponSet(Object value)
      This method is used to convert the value when the setValue method is called. The setValue method will call this method to obtain the converted value. The converted value will then be used as the value to set for the field.
      Parameters:
      value - the object value to convert before performing a set operation
      Returns:
      the converted value.

    • getFieldType

      public abstract Class getFieldType()
      Returns the class type for the field that this GeneralizedFieldHandler converts to and from. This should be the type that is used in the object model.
      Returns:
      the class type of of the field

    • setFieldHandler

      public final void setFieldHandler(FieldHandler handler)
      Sets the FieldHandler that this FieldHander delegates to. A call to this method must be made with a non-null FieldHandler before this GeneralizedFieldHandler can be used.
      Parameters:
      handler - the FieldHandler to delegate to

    • setCollectionIteration

      public void setCollectionIteration(boolean autoCollectionIteration)
      Sets whether or not this GeneralizedFieldHandler should automatically iterate over the collection returned by the target object and pass only the items (one by one) to the convertUponGet method. As of Castor 0.9.6 this is true by default.
      Parameters:
      autoCollectionIteration - a boolean that when true indicates that this GeneralizedFieldHandler should automatically iterate over a collection and pass only collection items to the convertUponGet method.

    • getValue

      public final Object getValue(Object object) throws IllegalStateException
      Returns the value of the field from the object.
      Specified by:
      getValue in interface FieldHandler
      Specified by:
      getValue in class FieldHandlerFriend
      Parameters:
      object - The object
      Returns:
      The value of the field
      Throws:
      IllegalStateException - The Java object has changed and is no longer supported by this handler, or the handler is not compatiable with the Java object

    • newInstance

      public Object newInstance(Object parent) throws IllegalStateException
      Creates a new instance of the object described by this field.
      Specified by:
      newInstance in interface FieldHandler
      Specified by:
      newInstance in class FieldHandlerFriend
      Parameters:
      parent - The object for which the field is created
      Returns:
      A new instance of the field's value
      Throws:
      IllegalStateException - This field is a simple type and cannot be instantiated

    • newInstance

      public Object newInstance(Object parent, Object[] args) throws IllegalStateException
      Creates a new instance of the object described by this field.
      Specified by:
      newInstance in class ExtendedFieldHandler
      Parameters:
      parent - The object for which the field is created
      args - the set of constructor arguments
      Returns:
      A new instance of the field's value
      Throws:
      IllegalStateException - This field is a simple type and cannot be instantiated

    • resetValue

      public final void resetValue(Object object) throws IllegalStateException, IllegalArgumentException
      Sets the value of the field to a default value.

      Reference fields are set to null, primitive fields are set to their default value, collection fields are emptied of all elements.

      Specified by:
      resetValue in interface FieldHandler
      Specified by:
      resetValue in class FieldHandlerFriend
      Parameters:
      object - The object
      Throws:
      IllegalStateException - The Java object has changed and is no longer supported by this handler, or the handler is not compatiable with the Java object
      IllegalArgumentException

    • setValue

      public final void setValue(Object object, Object value) throws IllegalStateException, IllegalArgumentException
      Sets the value of the field on the object.
      Specified by:
      setValue in interface FieldHandler
      Specified by:
      setValue in class FieldHandlerFriend
      Parameters:
      object - The object.
      value - The new value.
      Throws:
      IllegalStateException - The Java object has changed and is no longer supported by this handler, or the handler is not compatiable with the Java object.
      IllegalArgumentException - The value passed is not of a supported type.