org.geotools.coverage.processing

Class CoverageProcessor

Object

CoverageProcessor

public class CoverageProcessor
extends Object

Base class for coverage processor implementations.

Since:

2.2

Author:

Martin Desruisseaux (IRD), Simone Giannecchini, GeoSolutions S.A.S.

Field Summary

Fields

Modifier and Type	Field and Description
protected Hints	hints The rendering hints for JAI operations (never null).
static Logger	LOGGER The logger for coverage processing operations.
static Level	OPERATION The logging level for reporting coverage operations.
protected FactoryRegistry	registry The service registry for finding Operation implementations.

Constructor Summary

Constructors

Constructor and Description
CoverageProcessor() Constructs a coverage processor.
CoverageProcessor(RenderingHints hints) Constructs a default coverage processor.

Method Summary

Modifier and Type	Method and Description
protected void	addOperation(Operation operation) Add the specified operation to this processor.
Coverage	doOperation(ParameterValueGroup parameters) Applies a process operation to a coverage.
Coverage	doOperation(ParameterValueGroup parameters, Hints hints) Applies a process operation to a coverage.
static CoverageProcessor	getInstance() Returns a default processor instance.
static CoverageProcessor	getInstance(Hints hints) Returns a default processor instance.
Locale	getLocale() The locale for logging message or reporting errors.
Operation	getOperation(String name) Returns the operation for the specified name.
Collection<Operation>	getOperations() Retrieves grid processing operations information.
static Object	getParameter(ParameterBlockJAI parameters, String paramName)
Object	getRenderingHint(RenderingHints.Key key) Returns a rendering hint.
void	listOperations(Writer out) Lists a summary of all operations to the specified stream.
static void	main(String[] args) Dumps to the standard output stream a list of operations for the default processor.
void	printOperations(Writer out, String[] names) Prints a description of operations to the specified stream.
protected void	removeOperation(Operation operation) Removes the specified operation to this processor.
static void	removeOperationFromProcessors(String operationName) This method is called when the user has registered another OperationDescriptor and must remove the old operation instance from the processors.
void	scanForPlugins() Scans for factory plug-ins on the application class path.
static void	updateProcessors() This method is called when the user has registered another OperationDescriptor for an operation and requires to update the various CoverageProcessors.

Methods inherited from class Object

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

Field Detail

LOGGER

public static final Logger LOGGER

The logger for coverage processing operations.

OPERATION

public static final Level OPERATION

The logging level for reporting coverage operations. This level is equals or slightly lower than Level.INFO.

hints

protected final Hints hints

The rendering hints for JAI operations (never null). This field is usually given as argument to OperationJAI methods.

registry

protected final FactoryRegistry registry

The service registry for finding Operation implementations.

Constructor Detail

CoverageProcessor

public CoverageProcessor()

Constructs a coverage processor.

CoverageProcessor

public CoverageProcessor(RenderingHints hints)

Constructs a default coverage processor. 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:

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

Method Detail

getInstance

public static CoverageProcessor getInstance()

Returns a default processor instance.

Note: this is a temporary method, until we have GeoAPI interface for coverage processor and a factory finder for their implementations.

getInstance

public static CoverageProcessor getInstance(Hints hints)

Returns a default processor instance.

Note: this is a temporary method, until we have GeoAPI interface for coverage processor and a factory finder for their implementations.

updateProcessors

public static void updateProcessors()

This method is called when the user has registered another OperationDescriptor for an operation and requires to update the various CoverageProcessors.

removeOperationFromProcessors

public static void removeOperationFromProcessors(String operationName)

This method is called when the user has registered another OperationDescriptor and must remove the old operation instance from the processors.

Parameters:

operationName - Name of the operation to remove

getLocale

public Locale getLocale()

The locale for logging message or reporting errors. The default implementations returns the default locale. Subclasses can override this method if a different locale is wanted.

listOperations

public void listOperations(Writer out)
                    throws IOException

Lists a summary of all operations to the specified stream.

Parameters:

out - The destination stream.

Throws:

IOException - if an error occured will writing to the stream.

printOperations

public void printOperations(Writer out,
                            String[] names)
                     throws OperationNotFoundException,
                            IOException

Prints a description of operations to the specified stream. If the names array is non-null, then only the specified operations are printed. Otherwise, all operations are printed. The description details include operation names and lists of parameters.

Parameters:

out - The destination stream.

names - The operation to print, or an empty array for none, or null for all.

Throws:

IOException - if an error occured will writing to the stream.

OperationNotFoundException - if an operation named in names was not found.

addOperation

protected void addOperation(Operation operation)
                     throws IllegalStateException

Add 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.

removeOperation

protected void removeOperation(Operation operation)

Removes 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 remove.

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.

getOperation

public Operation getOperation(String name)
                       throws OperationNotFoundException

Returns the operation for the specified name.

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,
                            Hints hints)

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.geotools.util.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).

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.

doOperation

public Coverage doOperation(ParameterValueGroup parameters)
                     throws 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.geotools.util.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).

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.

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.

main

public static void main(String[] args)

Dumps to the standard output stream a list of operations for the default processor. If no argument is provided, then only a summary of operations is printed. If arguments are provided, then the operation parameters are printed for all operation names given in arguments. This method can been invoked from the command line. For example:

 java org.geotools.coverage.processing.DefaultProcessor Interpolate
 

Note for Windows users: If the output contains strange symbols, try to supply an "-encoding" argument. Example:

 java org.geotools.coverage.processing.DefaultProcessor -encoding Cp850
 

The codepage number (850 in the previous example) can be fetch from the DOS command line by entering the "chcp" command with no arguments.

getParameter

public static Object getParameter(ParameterBlockJAI parameters,
                                  String paramName)