com.luciad.wms.server

LuciadFusionClass ALcdMultiDimensionalModelProvider

java.lang.Object

com.luciad.wms.server.ALcdMultiDimensionalModelProvider

All Implemented Interfaces:

ILcdOGCModelProvider, ILcdDisposable, ILcdModelProvider, AutoCloseable

Direct Known Subclasses:

TLcdWMSModelProvider

public abstract class ALcdMultiDimensionalModelProvider
extends Object
implements ILcdModelProvider

Extension of ILcdModelProvider that provides support for multi-dimensional requests.

Next to the getModel(String) defined in ILcdModelProvider, it adds a method getModel(ALcdWMSLayer, ALcdWMSDimension[], TLcdWMSDimensionExtent[], TLcdWMSRequestContext) that returns a model for a specified layer and dimension parameters.

A client request that contains one or more dimensional parameters, does not necessarily comply to the actual dimension definitions. For example, if a client specifies a value for which no exact match is available, a nearest value may be used. For this purposes, the method getDimensionExtent(ALcdWMSLayer, ALcdWMSDimension, TLcdWMSDimensionExtent, TLcdWMSRequestContext) is used.

Constructor Summary

Constructors

Constructor and Description
ALcdMultiDimensionalModelProvider()

Method Summary

Modifier and Type	Method and Description
void	dispose() Disposes of this object and allows it to release any system resources that it is holding.
TLcdWMSDimensionExtent	getDimensionExtent(ALcdWMSLayer aLayer, ALcdWMSDimension aDimension, TLcdWMSDimensionExtent aSuppliedExtent, TLcdWMSRequestContext aWMSRequestContext) Returns the actual dimension extent, specifying the value(s)/interval(s) on which the supplied dimension extent can be mapped.
ILcdModel	getModel(ALcdWMSLayer aLayer, ALcdWMSDimension[] aDimensions, TLcdWMSDimensionExtent[] aDimensionExtent, TLcdWMSRequestContext aWMSRequestContext) Returns the ILcdModel corresponding to a layer and its dimensional parameters.
ILcdModel	getModel(String aSourceName, ALcdRequestContext aRequestContext) Returns the ILcdModel corresponding to a source name.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.luciad.wms.server.ILcdModelProvider

getModelUpdateSequence

Methods inherited from interface com.luciad.util.ILcdDisposable

close

Constructor Detail

ALcdMultiDimensionalModelProvider

public ALcdMultiDimensionalModelProvider()

Method Detail

getModel

public ILcdModel getModel(String aSourceName,
                          ALcdRequestContext aRequestContext)
                   throws IOException

Returns the ILcdModel corresponding to a source name.

This method is used for all ALcdWMSLayer objects that don't have any dimensions defined.

By default, an ILcdModelProvider implementation is used that maintains a cache for all decoded models. To prevent memory problems, it makes use of Soft reference objects, which are cleared at the discretion of the garbage collector in response to memory demand. Soft references are most often used to implement memory-sensitive caches.

Specified by:

getModel in interface ILcdOGCModelProvider

Specified by:

getModel in interface ILcdModelProvider

Parameters:

aSourceName - the source name of the model.

aRequestContext - the request context, which is an instance of type TLcdWMSRequestContext. This can be null if the method is called by a process which is not handling a request.

Returns:

the ILcdModel corresponding to a source name.

Throws:

IOException - if the model can not be returned (because decoding fails).

getModel

public ILcdModel getModel(ALcdWMSLayer aLayer,
                          ALcdWMSDimension[] aDimensions,
                          TLcdWMSDimensionExtent[] aDimensionExtent,
                          TLcdWMSRequestContext aWMSRequestContext)
                   throws IOException

Returns the ILcdModel corresponding to a layer and its dimensional parameters.

This method is used for all ALcdWMSLayer objects that have one or more dimensions defined in the capabilities.

The default implementation of this method sets the filtering value to the retrieved model via getModel(String, ALcdRequestContext). Because of the performance considerations, getModel(String, ALcdRequestContext) utilizes a model cache in which ILcdMultiDimensional models can be used in a thread safe manner. Thus this method relies on this idea that any multidimensional model retrieved from getModel is safe to alter filtering values.

If you ever override getModel(String, ALcdRequestContext) to add custom formats, you should ensure that the multidimensional models obtained from your method are either safe in means of filter setting or you override this method too to prevent possible threading issues.

Parameters:

aLayer - The layer for which a model must be retrieved.

aDimensions - The dimensions that are defined for the layer. These dimensions can be defined directly by the layer, or be inherited from a parent layer.

aDimensionExtent - The value(s) or interval(s) to be used for the dimensional parameters.

aWMSRequestContext - the WMS request context, which gives access to the original HttpServletRequest that was sent to the WMS and several other parameters.

Returns:

the ILcdModel corresponding to the layer and its dimensional parameters.

Throws:

IOException - if the model can not be returned (because decoding fails).

dispose

public void dispose()

Description copied from interface: ILcdDisposable

Disposes of this object and allows it to release any system resources that it is holding.

The result of calling any other method (other than finalize) on this object subsequent to a call to this method is undefined.

Specified by:

dispose in interface ILcdOGCModelProvider

Specified by:

dispose in interface ILcdDisposable

getDimensionExtent

public TLcdWMSDimensionExtent getDimensionExtent(ALcdWMSLayer aLayer,
                                                 ALcdWMSDimension aDimension,
                                                 TLcdWMSDimensionExtent aSuppliedExtent,
                                                 TLcdWMSRequestContext aWMSRequestContext)

Returns the actual dimension extent, specifying the value(s)/interval(s) on which the supplied dimension extent can be mapped. This conversion should comply to the following rules and to the properties of the supplied dimension:

• If a supplied value or interval has an exact match, it must be copied to the returned dimension extent.
• If a supplied value or interval has no exact match:
  • If a nearest match may be used (if isNearestValue() in the supplied ALcdWMSDimension object returns true), a nearest match must be determined and added to the returned dimension extent.
  • If no nearest match may be used, no value or interval for the supplied value/interval should be added to the returned dimension extent. If it was the only specified value or interval, an empty dimension extent or null must be returned
  .

Before this method is invoked, the following measures are already taken:

• If the client did not specify a parameter for the dimension, the default value is used in the supplied extent object and an appropriate HTTP response header is automatically added to the response. If no default value was available, a service exception report was sent to the client.
• If the client did specify a parameter that did not complied to the format defined in the WMS specification, service exception reports was sent to the client.
• If the client did specify a parameter containing multiple values or intervals while this was not allowed according to ALcdWMSDimension.isMultipleValues(), a service exception reports was sent to the client.

After this method is invoked, the following measures are taken:

• If the resolved extent contains less values or intervals than the supplied extent, a service exception report is sent to the client.
• If the resolved extent contains different values or intervals than the ones defined in the original extent, an appropriate HTTP response header is automatically added to the response.

This implementation provides by default support for dimensions that use numeric values. If other dimensions are used (e.g. dates or other character-based dimensions, etc.), a proper implementation should be provided for these dimensions.

Parameters:

aLayer - The layer for which a dimension was specified in the client request.

aDimension - The dimension for which a value was specified in the client request. Note that this dimension can be defined in a parent layer of the specified layer, since dimension definitions are inherited if none are defined by the child layer.

aSuppliedExtent - The value(s)/interval(s) specified for the dimension in the client request.

aWMSRequestContext - the WMS request context, which gives access to the original HttpServletRequest that was sent to the WMS and several other parameters.

Returns:

The actual dimension extent.