|
NASA World Wind WMS | ||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
public interface MapGenerator
Concrete implementations of MapGenerator
are the means by which geospatial data are introduced and served
by the WMS. A MapGenerator
embodies all the knowledge necessary to read a particular class of geospatial data.
This includes interpretation of the file formats, along with awareness of any spatial indexing scheme or other
organization of files on the disk. It also includes the ability to extract subregions of the data and likely
mosaic pieces together in response to arbitrary WMS GetMap requests.
Instances of MapGenerator
classes further embody the state needed to manage a particular set of data. Multiple
instances of the same class might therefore be used to manage differing collections of the same data type
that might be organized by region, scale, or other arbitrary organization. The initialize()
method is called once at startup time to give the MapGenerator
instance a chance to perform any
processing required before GetMap requests can be satisfied.
Per-request state is managed by instances of ServiceInstance
. As the WMS identifies a particular MapGenerator
to field a GetMap request, it obtains an instance of ServiceInstance
from the MapGenerator
via a call to
getServiceInstance()
. The WMS then invokes the serviceRequest()
method of the
ServiceInstance
, in which the MapGenerator
attempts to generate the requested imagery. If successful, an
instance of ImageFormatter
is returned, which the WMS uses to deliver the map in the requested image
format. Finally, the WMS calls the freeResources()
on the ServiceInstance
, which gives the
MapGenerator
a chance to reclaim any resources, such as temporary files, etc. If the MapGenerator
is unable
to satisfy the GetMap request, it should throw a WMSServiceException
with appropriate descriptive text as to
why the request failed.
MapGenerators
are configured into the WMS via <MapSource>
elements in the
WEB-INF/config.xml
file. See the javadoc Overview for details.
Nested Class Summary | |
---|---|
static interface |
MapGenerator.ServiceInstance
Encapsulates per-request state needed to generate a response to a GetMap request. |
Method Summary | |
---|---|
gov.nasa.worldwind.geom.Sector |
getBBox()
Returns the bounding-box for the geospatial dataset managed by the MapGenerator instance. |
String[] |
getCRS()
Returns the coordinate-reference systems (CRS) that the MapGenerator is capable of using to generate map requests. |
MapGenerator.ServiceInstance |
getServiceInstance()
Called by the WMS to return an instance of ServiceInstance to field a GetMap request. |
boolean |
initialize(MapSource mapSource)
Gives the MapGenerator implementation an opportunity to perform any needed initialization, prior to fielding GetMap requests. |
Method Detail |
---|
gov.nasa.worldwind.geom.Sector getBBox()
String[] getCRS()
MapGenerator.ServiceInstance getServiceInstance()
boolean initialize(MapSource mapSource) throws IOException, WMSServiceException
mapSource
-
IOException
WMSServiceException
|
NASA World Wind WMS | ||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |