GetMap Requests |
Request parameters of the GetMap operation are shown in the following table:
Table 1 Request parameters of the GetMap operation
Request Parameters | O/M /Optional | Description |
VERSION=version |
Mandatory |
Request version numbers. |
REQUEST=GetMap |
Mandatory |
Request names. Requests the GetMap operation, and the request name needs to be set as "GetMap". |
LAYERS=layer_list |
Mandatory |
Lists of map layers. Map layers are separated by half-angle English commas. The leftmost layer is at the bottom, and the next layer is placed above the previous one, and so on. The layer name is the character data content of the <Layer><Name> element in service metadata. The optional <LayerLimit> element in service metadata specifies maximum layer number that can be requested. |
STYLES=style_list |
Mandatory |
Style lists of request layers, and layer styles are separated by English commas. Each STYLES value is associated with one LAYERS parameter value. The layer name is the <Style><Name> element value defined in service metadata. If requests a Style that does not exist, the server will return a service exception (code=StyleNotDefined). SuperMap iServer has not realized at present. This value should be set as empty. |
CRS=namespace:identifier |
Mandatory |
Coordinate reference system. This parameter value should be CRS declared by the server in the GetCapabilities operation. If the request contains a CRS that the server does not support, the server will throw a service exception (code = "InvalidCRS"). Please refer to Coordinate reference system supported by iServer OGC services. |
BBOX=minx,miny,maxx,maxy |
Mandatory |
BoundingBox. Represents map extents. This parameter value is a string of real numbers separated by half-angle English commas, in the form of "minx, miny, maxx, maxy", representing minimum X, minimum Y, maximum X and maximum Y of area coordinates in the specified CRS respectively. If the request contains an invalid BBOX, such as situations in which minimum X is larger than or equal to maximum X, or minimum Y is larger than or equal to maximum Y, the server will throw a service exception. If the extent represented by the requested BBOX does not overlap the BoundingBox in service metadata, the server will return an empty content (an empty map, or a graphic element file without subelements). |
WIDTH=output_width |
Mandatory |
Width in pixels of map picture. |
HEIGHT=output_height |
Mandatory |
Pixel heights of map pictures. |
FORMAT=output_format |
Mandatory |
Output formats of maps. One of Format in GetMap declared in capabilities documents of the WMS server. |
TRANSPARENT=TRUE|FALSE |
Optional |
Whether the map background is transparent (the default is FALSE). |
BGCOLOR=color_value |
Optional |
Hexadecimal red-green-blue color values of background colors (the default is 0xFFFFFF). |
EXCEPTIONS=exception_format |
Optional |
Exception error report formats of WMS (the default is XML). This parameter value must be one of Exception in service metadata. |
TIME=time |
Optional |
Time value of layer desired. SuperMap iServer has not realized this functionality at present. |
ELEVATION=elevation |
Optional |
Elevations of layers that are expected to get. SuperMap iServer has not realized this functionality at present. |
Other sample dimension(s) |
Optional |
Other proper dimension values. SuperMap iServer has not realized this functionality at present. |
Request methods of the GetMap operation are as follows:
<ServiceRoot>?VERSION=version&REQUEST=GetMap&LAYERS=layer_list&STYLES=style_list &CRS=namespace:identifier&BBOX=minx,miny,maxx,maxy&WIDTH=output_width &HEIGHT=output_height&FORMAT=output_format
ServiceRoot is the service URI root directory. Please see Setting the Service URI.
For example, when the local SuperMap iServer WMS 1.3.0 service has been successfully started, the URI to access the GetMap operation is URI: http://localhost:8090/iserver/services/maps/wms111/WorldMap_Day?VERSION=1.1.1&REQUEST=GetMap&layers=0.11&STYLES=&SRS=EPSG:4326&BBOX=-180.0,-90.0,180.0,90.0&WIDTH=800&HEIGHT=400&FORMAT=image/png.
Please refer to Response example to see the result.