Package org.apache.sis.storage

Class FeatureNaming<E>

java.lang.Object
org.apache.sis.storage.FeatureNaming<E>
Type Parameters:
E - the type of elements associated with the names.
public class FeatureNaming<E> extends Object
Helper class for mapping GenericName instances and their shortened names to features. The features are typically represented by instances of FeatureType or Coverage (sometimes seen as a kind of features), but this class actually puts no restriction on the kind of object associated to GenericNames; DataStore implementations are free to choose their internal object. Those objects can be stored and fetched using the String representation of their name as given by GenericName.toString(), or a shortened name when there is no ambiguity. Note that search is case sensitive.
Example: a data store may contain a FeatureType named "foo:bar". If that feature type has been binded like below: Then the two following lines return the same instance:
Note that contrarily to the standard Map.get(Object) method contract, the get(…) method defined in this class throws an exception instead of returning null if no unambiguous mapping can be established for the given name. This behavior allows FeatureNaming to produce an error message telling why the operation cannot succeed.

Managing the list of generic names

This class does not memorize the list of added GenericName instances. Instead, this class memorizes only their string representations, thus protecting the binding from any change in the original GenericName instances. The list of feature names should instead be included in the ISO 19115 metadata returned by DataStore.getMetadata(). The path to feature names is:
metadata / contentInfo / featureTypes / featureTypeName
Note that above metadata information are not necessarily structured as a flat list; a DataStore may group some feature information in different FeatureCatalogueDescription instances. This is one reason why we let the data store manages GenericName lists itself.

Thread safety

A FeatureNaming instance is thread-safe only if constructed once and never modified after publication. For example, it is safe to initialize a FeatureNaming in a DataStore or DataStoreProvider constructor if the result is stored in a private final field with no public accessor and no call to add(…) or remove(…) methods after construction. If this condition does not hold, then synchronization (if desired) is caller's responsibility. The caller is typically the DataStore implementation which contains this FeatureNaming instance.
Since:
0.8
Version:
0.8
Author:
Martin Desruisseaux (Geomatys)
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    FeatureNaming()
    Creates a new "GenericName to object" mapping.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(DataStore store, org.opengis.util.GenericName name, E value)
    Adds a value for the given name if none exist.
    E
    get(DataStore store, String name)
    Returns the value associated to the given name (case sensitive).
    boolean
    remove(DataStore store, org.opengis.util.GenericName name)
    Removes the value associated to the given name.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • FeatureNaming

      public FeatureNaming()
      Creates a new "GenericName to object" mapping.

  • Method Details

    • get

      public E get(DataStore store, String name) throws IllegalNameException
      Returns the value associated to the given name (case sensitive).
      Parameters:
      store - the data store for which to get a value, or null if unknown.
      name - the name for which to get a value.
      Returns:
      value associated to the given object.
      Throws:
      IllegalNameException - if the given name was not found or is ambiguous.

    • add

      public void add(DataStore store, org.opengis.util.GenericName name, E value) throws IllegalNameException
      Adds a value for the given name if none exist. If a previous value already exists for the given name, then an exception is thrown.
      Parameters:
      store - the data store for which to add a value, or null if unknown.
      name - the name for which to add a value.
      value - the value to add (cannot be null).
      Throws:
      IllegalNameException - if another element is already registered for the given name.

    • remove

      public boolean remove(DataStore store, org.opengis.util.GenericName name) throws IllegalNameException
      Removes the value associated to the given name. If no value is associated to the given name, then this method does nothing.
      Parameters:
      store - the data store for which to remove a value, or null if unknown.
      name - the name for which to remove value.
      Returns:
      true if the value was removed, or false if no value was defined for the given name.
      Throws:
      IllegalNameException - if inconsistency are found between the given name and the one which was given to the add(…) method. An example of inconsistency is a name having the same string representation, but for which ScopedName.tail() returns different values.