Class DefaultFeatureType

Object
AbstractIdentifiedType
DefaultFeatureType
All Implemented Interfaces:
Serializable, Deprecable
public class DefaultFeatureType extends AbstractIdentifiedType
Abstraction of a real-world phenomena. A Feature­Type instance describes the class of all feature instances of that type.
Analogy: compared to the Java language, Feature­Type is equivalent to Class while Feature instances are equivalent to Object instances of that class.
Warning: This class is expected to implement a GeoAPI Feature­Type interface in a future version. When such interface will be available, most references to Default­Feature­Type in the API will be replaced by references to the Feature­Type interface.

Naming

The feature type name is mandatory and should be unique. Those names are the main criterion used for deciding if a feature type is assignable from another type. Names can be scoped for avoiding name collision.

Properties and inheritance

Each feature type can provide descriptions for the following properties: In addition, a feature type can inherit the properties of one or more other feature types. Properties defined in the sub-type can override properties of the same name defined in the super-types, provided that values of the sub-type property are assignable to the super-type property.
Analogy: compared to the Java language, the above rule is similar to overriding a method with a more specific return type (a.k.a. covariant return type). This is also similar to Java arrays, which are implicitly covariant (i.e. String[] can be cast to Char­Sequence[], which is safe for read operations but not for write operations — the latter may throw Array­Store­Exception).

Instantiation

Default­Feature­Type can be instantiated directly by a call to its constructor. But a more convenient approach may be to use the Feature­Type­Builder instead, which provides shortcuts for frequently-used operations like creating various Generic­Name instances sharing the same namespace.

Immutability and thread safety

Instances of this class are immutable if all properties (Generic­Name and International­String instances) and all arguments (Attribute­Type instances) given to the constructor are also immutable. Such immutable instances can be shared by many objects and passed between threads without synchronization.
Since:
0.5
See Also:

  • Constructor Details

  • Method Details

    • isAbstract

      public final boolean isAbstract()
      Returns true if the feature type acts as an abstract super-type. Abstract types cannot be instantiated.
      Returns:
      true if the feature type acts as an abstract super-type.

    • isSimple

      public boolean isSimple()
      Returns true if this feature type contains only attributes with [1 … 1] multiplicity, or operations (no feature association). Such feature types can be handled as a records.
      Returns:
      true if this feature type contains only simple attributes or operations.

    • isAssignableFrom

      public boolean isAssignableFrom(DefaultFeatureType type)
      Returns true if this type is same or a super-type of the given type. The check is based mainly on the feature type name, which should be unique. However, as a safety, this method also checks that all properties in this feature type is assignable from a property of the same name in the given type.

      Constraints

      • If A is assignable from B and B is assignable from C, then A is assignable from C.
      Analogy: if we compare Feature­Type to Class in the Java language, then this method is equivalent to Class​.is­Assignable­From(Class).
      Parameters:
      type - the type to be checked.
      Returns:
      true if instances of the given type can be assigned to association of this type.

    • getSuperTypes

      public final Set<DefaultFeatureType> getSuperTypes()
      Returns the direct parents of this feature type.
      Analogy: if we compare Feature­Type to Class in the Java language, then this method is equivalent to Class​.get­Superclass() except that feature types allow multi-inheritance.
      Warning: The type of list elements will be changed to Feature­Type if and when such interface will be defined in GeoAPI.

      API note

      This method is final because it is invoked (indirectly) by constructors, and invoking a user-overrideable method at construction time is not recommended. Furthermore, many Apache SIS methods need guarantees about the stability of this collection.
      Returns:
      the parents of this feature type, or an empty set if none.

    • getProperties

      public Collection<AbstractIdentifiedType> getProperties(boolean includeSuperTypes)
      Returns any feature operation, any feature attribute type and any feature association role that carries characteristics of a feature type. The returned collection will include the properties inherited from the super-types only if include­Super­Types is true.
      Warning: The type of list elements will be changed to Property­Type if and when such interface will be defined in GeoAPI.
      Parameters:
      include­Super­Types - true for including the properties inherited from the super-types, or false for returning only the properties defined explicitly in this type.
      Returns:
      feature operation, attribute type and association role that carries characteristics of this feature type (not including parent types).

    • hasProperty

      public boolean hasProperty(String name)
      Returns true if and only if an attribute, operation or association role of the given name exists in this feature type or in one of its super-types. If this method returns true, then calls to get­Property(name) will not throw Illegal­Argument­Exception.
      Parameters:
      name - the name of the property to search.
      Returns:
      whether an attribute, operation or association role exists for the given name.
      Since:
      1.6

    • getProperty

      public AbstractIdentifiedType getProperty(String name) throws IllegalArgumentException
      Returns the attribute, operation or association role for the given name. The method searches in this feature type and in all super-types.
      Warning: The type of returned element will be changed to Property­Type if and when such interface will be defined in GeoAPI.
      Parameters:
      name - the name of the property to search.
      Returns:
      the property for the given name, or null if none.
      Throws:
      Illegal­Argument­Exception - if the given argument is not a property name of this feature.
      See Also:

    • newInstance

      public AbstractFeature newInstance() throws IllegalStateException
      Creates a new feature instance of this type.
      Analogy: if we compare Feature­Type to Class and Feature to Object in the Java language, then this method is equivalent to Class​.new­Instance().
      Returns:
      a new feature instance.
      Throws:
      Illegal­State­Exception - if this feature type is abstract.

    • hashCode

      public int hashCode()
      Returns a hash code value for this feature type.
      Overrides:
      hash­Code in class Abstract­Identified­Type
      Returns:
      the hash code for this type.

    • equals

      public boolean equals(Object obj)
      Compares this feature type with the given object for equality.
      Overrides:
      equals in class Abstract­Identified­Type
      Parameters:
      obj - the object to compare with this type.
      Returns:
      true if the given object is equal to this type.

    • toString

      public String toString()
      Formats this feature in a tabular format.
      Overrides:
      to­String in class Object
      Returns:
      a string representation of this feature in a tabular format.
      See Also:

    • getName

      GenericName getName()