org.geotoolkit.coverage.processing
Class DefaultCoverageProcessor

Object
  Factory
      AbstractCoverageProcessor
          DefaultCoverageProcessor

All Implemented Interfaces:

Localized, GridCoverageProcessor

@ThreadSafe
public class DefaultCoverageProcessor
extends AbstractCoverageProcessor

Default implementation of a Coverage processor. This default implementation makes the following assumptions:

• Operations are declared in the META-INF/services/org.opengis.coverage.processing.Operation file.
• Operations are actually instances of AbstractOperation (note: this constraint may be relaxed in a future version after GeoAPI interfaces for grid coverage will be redesigned).
• Operation parameter names are case-insensitive.
• Most operations are backed by Java Advanced Imaging.

Note: This implementation does not cache produced coverages. Since coverages may be big, consider wrapping DefaultCoverageProcessor instances in CachingCoverageProcessor.

Since:

1.2

Version:

3.02

Author:

Martin Desruisseaux (IRD)

Module:

coverage/geotk-coverage (download)

View source code for this class

Nested Class Summary

Nested classes/interfaces inherited from class Factory

Factory.Availability, Factory.Organizer

Field Summary

Fields inherited from class AbstractCoverageProcessor

LOGGER, OPERATION

Fields inherited from class Factory

EMPTY_HINTS, hints

Constructor Summary

DefaultCoverageProcessor(Hints userHints)
Constructs a coverage processor from the given hints.

Method Summary

protected void	addOperation(Operation operation) Adds the specified operation to this processor.
Coverage	doOperation(ParameterValueGroup parameters) Applies a process operation to a coverage.
Operation	getOperation(String name) Returns the operation for the specified name.
Collection<Operation>	getOperations() Retrieves grid processing operations information.
Object	getRenderingHint(RenderingHints.Key key) Returns a rendering hint.
void	scanForPlugins() Scans for factory plug-ins on the application class path.

Methods inherited from class AbstractCoverageProcessor

getInstance, getLocale, listOperations, printOperations

Methods inherited from class Factory

availability, dispose, equals, getImplementationHints, hasCompatibleHints, hashCode, setOrdering, toString

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DefaultCoverageProcessor

public DefaultCoverageProcessor(Hints userHints)

Constructs a coverage processor from the given hints. The scanForPlugins() method will be automatically invoked the first time an operation is required. Additional operations can be added by subclasses with the addOperation(org.opengis.coverage.processing.Operation) method.

Rendering hints will be initialized with the following hints:

• JAI.KEY_REPLACE_INDEX_COLOR_MODEL set to Boolean.FALSE.
• JAI.KEY_TRANSFORM_ON_COLORMAP set to Boolean.FALSE.

Parameters:

userHints - A set of additional rendering hints, or null if none.

Method Detail

addOperation

protected void addOperation(Operation operation)
                     throws IllegalStateException

Adds the specified operation to this processor. This method is usually invoked at construction time before this processor is made accessible.

Parameters:

operation - The operation to add.

Throws:

IllegalStateException - if an operation already exists with the same name.

getOperations

public Collection<Operation> getOperations()

Retrieves grid processing operations information. Each operation information contains the name of the operation as well as a list of its parameters.

Specified by:

getOperations in interface GridCoverageProcessor

Specified by:

getOperations in class AbstractCoverageProcessor

Returns:

The available processing operations

getOperation

public Operation getOperation(String name)
                       throws OperationNotFoundException

Returns the operation for the specified name.

Specified by:

getOperation in class AbstractCoverageProcessor

Parameters:

name - Name of the operation (case insensitive).

Returns:

The operation for the given name.

Throws:

OperationNotFoundException - if there is no operation for the specified name.

getRenderingHint

public final Object getRenderingHint(RenderingHints.Key key)

Returns a rendering hint.

Parameters:

key - The hint key (e.g. Hints.JAI_INSTANCE).

Returns:

The hint value for the specified key, or null if there is no hint for the specified key.

doOperation

public Coverage doOperation(ParameterValueGroup parameters)
                     throws CoverageProcessingException,
                            OperationNotFoundException

Applies a process operation to a coverage. The default implementation checks if source coverages use an interpolation, and then invokes AbstractOperation.doOperation(org.opengis.parameter.ParameterValueGroup, org.geotoolkit.factory.Hints). If all source coverages used the same interpolation, then this interpolation is applied to the resulting coverage (except if the resulting coverage has already an interpolation).

Specified by:

doOperation in class AbstractCoverageProcessor

Parameters:

parameters - Parameters required for the operation. The easiest way to construct them is to invoke operation.getParameters() and to modify the returned group.

Returns:

The result as a coverage.

Throws:

OperationNotFoundException - if there is no operation for the parameter group name.

CoverageProcessingException - if the operation can not be executed.

scanForPlugins

public void scanForPlugins()

Scans for factory plug-ins on the application class path. This method is needed because the application class path can theoretically change, or additional plug-ins may become available. Rather than re-scanning the classpath on every invocation of the API, the class path is scanned automatically only on the first invocation. Clients can call this method to prompt a re-scan. Thus this method need only be invoked by sophisticated applications which dynamically make new plug-ins available at runtime.