The information in this guide is only needed if you want to perform your own WMTS request, for example a |
Setting up a WMTS client
To set up a connection to a WMTS service you first need to create a new WMTS client:
String serverURL = "https://sampleservices.luciad.com/wmts";
TLcdWMTSClient wmtsClient = new TLcdWMTSClient(new URI(serverURL));
You can use one client instance for just one OGC service. Therefore, you must identify the service at construction time.
The client you just created will connect with the WMTS service by retrieving its capabilities. As described in the OGC specifications, a version negotiation process will also take place to determine a commonly supported version between the web service and the web client.
Introduction to OGC requests
Creating and sending OGC requests
Requests are modeled by the interface
ILcdOWSRequest
,
which supports (if applicable):
-
Key-value pair requests
-
XML-encoded requests
-
REST requests
You cannot instantiate these request objects directly. Instead, they are created by factory methods in the client.
The created requests are automatically initialized with the parameters SERVICE
, REQUEST
and VERSION
.
The value of the VERSION
parameter corresponds to the version agreed during the version negotiation
process upon initialization.
Depending on the request, further parameters can or must be defined before sending the request to an OGC service.
The OWS transport layer guide contains more information about the use of ILcdOWSRequest
instances.
Receiving OGC responses
Each request will have a specific type of response.
The LuciadLightspeed OGC Web Client Suite offer a number of predefined response types.
The general response type
TLcdOWSInputStream
is an extension of java.io.FilterInputStream
, which adds the content type and some extra metadata to the result stream.
Creating OGC custom requests
It is also possible to create custom requests. To support custom requests, you must override the appropriate client class, to provide access to the new requests.
Extensions can perform custom ILcdOWSRequest
implementations by invoking the protected method performRequest
.
Next to the request itself, the name of the operation associated with the request is required. This operation must correspond to an operation defined in the capabilities of the OGC service.
For example, GetCapabilities
is a mandatory operation supported by each OGC service.
If the operation is not supported, the request will not be performed and an UnsupportedOperationException
is thrown.
You can retrieve the list of available operations at an OGC service through the method decodeOperations
,
which returns a list of
TLcdOWSOperation
objects.
Requesting WMTS data
With the TLcdWMTSClient
, you can list the available WMTS layers using the getLayers()
method.
A WMTS layer contains the details about the available image formats, the available styles and the available dimensions.
When the tiling structure of a WMTS layer is not a quadtree, you can still visualize all the levels but you may have a decrease
in the performance.
You can use TLcdWMTSLayer.isTileStructureQuadTree()
to verify whether the tile structure is quadtree or not.