Class IdentifiedObjectFinder

Object
IdentifiedObjectFinder
Direct Known Subclasses:
Identified­Object­Finder​.Wrapper
public class IdentifiedObjectFinder extends Object
Searches in an authority factory for objects approximately equal to a given object. This class can be used for fetching a fully defined identified object from an incomplete one, for example from an object without "ID[…]" or "AUTHORITY[…]" element in Well Known Text.

The steps for using Identified­Object­Finder are:

  1. Get a new instance by calling Geodetic­Authority­Factory​.new­Identified­Object­Finder().
  2. Optionally configure that instance by calling its setter methods.
  3. Perform a search by invoking the find(Identified­Object) or find­Singleton(Identified­Object) method.
  4. The same Identified­Object­Finder instance can be reused for consecutive searches.

Thread safety

Identified­Object­Finder are not guaranteed to be thread-safe even if the underlying factory is thread-safe. If concurrent searches are desired, then a new instance should be created for each thread.
Since:
0.7
See Also:

  • Field Details

    • factory

      protected final AuthorityFactory factory
      The factory to use for creating objects. This is the factory specified at construction time.

  • Constructor Details

  • Method Details

    • getSearchDomain

      public IdentifiedObjectFinder.Domain getSearchDomain()
      Returns the domain of the search (for example, whether to include deprecated objects in the search). If the domain is DECLARATION, then the find(…) method will only perform a fast lookup based on the identifiers and the names of the object to search. Otherwise, an exhaustive scan of the geodetic dataset will be performed (may be slow).

      The default value is Identified­Object­Finder​.Domain​.VALID_DATASET.

      Returns:
      the domain of the search.

    • setSearchDomain

      public void setSearchDomain(IdentifiedObjectFinder.Domain domain)
      Sets the domain of the search (for example, whether to include deprecated objects in the search). If this method is never invoked, the default value is Identified­Object­Finder​.Domain​.VALID_DATASET.
      Parameters:
      domain - the domain of the search.

    • isIgnoringAxes

      public boolean isIgnoringAxes()
      Returns true if the search should ignore coordinate system axes. The default value is false.
      Returns:
      true if the search should ignore coordinate system axes.

    • setIgnoringAxes

      public void setIgnoringAxes(boolean ignore)
      Sets whether the search should ignore coordinate system axes. If this property is set to true, then the search will compare only the coordinate system type and dimension. The axis names, orientation and units will be ignored. For example, the find(…) method may return a Coordinate Reference System object with (latitude, longitude) axes even if the given object had (longitude, latitude) axes.
      Parameters:
      ignore - true if the search should ignore coordinate system axes.

    • findSingleton

      @OptionalCandidate public IdentifiedObject findSingleton(IdentifiedObject object) throws FactoryException
      Looks up only one object which is approximately equal to the specified object. This method invokes find(Identified­Object), then examine the returned Set as below:
      • If the set is empty, then this method returns null.
      • If the set contains exactly one element, then this method returns that element.
      • If the set contains more than one element, but only one element has the same axis order than object and all other elements have different axis order, then this method returns the single element having the same axis order.
      • Otherwise this method considers that there is ambiguity and returns null.
      Parameters:
      object - the object looked up.
      Returns:
      the identified object, or null if none or ambiguous.
      Throws:
      Factory­Exception - if an error occurred while fetching the authority code candidates.

    • find

      public Set<IdentifiedObject> find(IdentifiedObject object) throws FactoryException
      Looks up objects which are approximately equal to the specified object. This method tries to instantiate objects identified by the set of candidate codes using the authority factory specified at construction time. Factory­Exceptions thrown during object creations are logged and otherwise ignored. The successfully created objects which are equal to the specified object in the sense of Comparison­Mode​.APPROXIMATE or ALLOW_VARIANT (depending on whether axes are ignored) are included in the returned set.

      Exception handling

      This method may return a lazy set, in which case some checked exceptions may occur at iteration time. These exceptions are wrapped in a Backing­Store­Exception.
      Parameters:
      object - the object looked up.
      Returns:
      the identified objects, or an empty set if not found.
      Throws:
      Factory­Exception - if an error occurred while fetching the authority code candidates.

    • getCodeCandidates

      protected Iterable<String> getCodeCandidates(IdentifiedObject object) throws FactoryException
      Returns a set of authority codes that may identify the same object as the specified one. The codes may be determined from object identifiers, names, aliases or extensive search in the geodetic dataset. The effort in populating the returned set is specified by the search domain. The returned set should contain at least the codes of every objects in the search domain that are approximately equal to the specified object. However, the set may conservatively contain the codes for more objects if an exact search is too expensive.

      This method is invoked by the default find(Identified­Object) method implementation. The caller iterates through the returned codes, instantiates the objects and compares them with the specified object in order to determine which codes are really matching. The iteration order should be the preference order.

      Exceptions during iteration

      An unchecked Backing­Store­Exception may be thrown during the iteration if the implementation fetches the codes lazily (when first needed) from the authority factory, and that action failed. The exception cause is often the checked Factory­Exception.

      Default implementation

      The default implementation returns codes defined from object​.get­Identifiers(), or factory​.get­Authority­Codes(type) where type is derived from object class, or a combination of both collection, depending on the search domain. Subclasses should override this method in order to return a smaller set, if they can.
      Parameters:
      object - the object looked up.
      Returns:
      a set of code candidates.
      Throws:
      Factory­Exception - if an error occurred while fetching the set of code candidates.
      See Also: