Package org.geotools.api.feature.type

Interface PropertyDescriptor

All Known Subinterfaces:
AssociationDescriptor, AttributeDescriptor, ChoiceAttributeType, ChoiceGeometryType, GeometryDescriptor, Operation
All Known Implementing Classes:
AssociationDescriptorImpl, AttributeDescriptorImpl, ChoiceGeometryTypeImpl, GeometryDescriptorImpl, PropertyDescriptorImpl
public interface PropertyDescriptor
Describes a Property, and how it relates to its containing entity, which is often a ComplexAttribute.

A property descriptor defines the following about the property:

  • type of the property
  • the name of the property
  • number of allowable occurrences of the property
  • nilability of the property

The concept of a descriptor is similar to that of a element declaration in xml. Consider the following xml schema definition: 

   <complexType name="someComplexType">
     <sequence>
       <element name="foo" minOccurs="2" maxOccurs="4" type="xs:string" nillable="false"/>
     <sequence>
   <complexType>

In the above, the element declaration named "foo" maps to a property descriptor. From the above schema, the following property descriptor would result: 
  //the complex type
  ComplexType complexType = ...;

  //get the descriptor
  PropertyDescriptor descriptor = complexType.getProperty( "foo" );

  //make the following assertions
  descriptor.getName().getLocalPart().equals( "foo" );

  descriptor.getType().getName().getNamespaceURI().equals( "http://www.w3.org/2001/XMLSchema" )
  descriptor.getType().getName().getLocalPart().equals( "string" );
  descriptor.getMinOccurs() == 2;
  descriptor.getMaxOccurs() == 4;
  descriptor.isNillable() == true;

  //the complex attribute
  ComplexAttribute complexAttribute = ...
  complexAttribute.getType() == complexType;

  //get the properties
  Collection properties = complexAttribute.getProperties( "foo" );

  //make assertions about properties
  properties.size() >= 2;  //minOccurs = 2
  properties.size() <= 4; //maxOccurs = 4

  for ( Property p : properties ) {
      p.getDescriptor() == descriptor

      p.getValue() != null; //nilable = false
      p.getType().getBinding() == String.class; //type = xs:string
      p.getValue() instanceof String; //type = xs:string
  }

Author:
Jody Garnett, Refractions Research, Justin Deoliveira, The Open Planning Project

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    getMaxOccurs()
    The maximum number of occurrences of the property within its containing entity.
    int
    getMinOccurs()
    The minimum number of occurrences of the property within its containing entity.
    Name
    getName()
    The name of the property defined by the descriptor, with respect to its containing type or entity..
    PropertyType
    getType()
    The type of the property defined by the descriptor.
    Map<Object,Object>
    getUserData()
    A map of "user data" which enables applications to store "application-specific" information against a property descriptor.
    boolean
    isNillable()
    Flag indicating if null is an allowable value for the property.

  • Method Details

    • getType

      PropertyType getType()
      The type of the property defined by the descriptor.

      This value should never be null. The type contains information about the value of the property such as its java class.

    • getName

      Name getName()
      The name of the property defined by the descriptor, with respect to its containing type or entity..

      This value may be null in some instances. Also note that this is not the same name as getType().getName(). The former is the name of the instance, the latter is the name of the type of the instance.

    • getMinOccurs

      int getMinOccurs()
      The minimum number of occurrences of the property within its containing entity.

      This value is always an integer greater than or equal to zero.

      Returns:
      An integer >= 0

    • getMaxOccurs

      int getMaxOccurs()
      The maximum number of occurrences of the property within its containing entity.

      This value is a positive integer. A value of -1 means that the max number of occurrences is unbounded.

      Returns:
      An integer >= 0, or -1.

    • isNillable

      boolean isNillable()
      Flag indicating if null is an allowable value for the property.
      Returns:
      true if the property is allowed to be null, otherwise false.

    • getUserData

      Map<Object,Object> getUserData()
      A map of "user data" which enables applications to store "application-specific" information against a property descriptor.
      Returns:
      A map of user data.