World Wind Java开发之十三——加载Geoserver发布的WMS服务

ゝ一纸荒年。 2022-08-06 15:12 184阅读 0赞

这篇是转载的平常心博客，原地址见：[http://www.v5cn.cn/?p=171][http_www.v5cn.cn_p_171]

## 1、WMSTiledImageLayer类说明 ##

一个WMSTiledImageLayer类对象只能对应一个WMS发布的服务图层，使用WMS服务时需要使用到WMS元数据描述类WMSCapabilities对象，我们使用WMSCapabilites类的静态方法retrieve来获得它的对象。WMSCapabilites对象可以包含WMS服务中所以的图层和图层样式，我们通过把需要显示的图层名称保存到AVList对象中，然后通过WMSCapabilites对象和AVList来创建WMSTiledImageLayer对象。我们可以通过一个请求地址来查看WMS服务所包含的元数据。例如：http://127.0.0.1:8080/geoserver/PostGIS/wms?request=GetGapabilities&Service=WMS 问号后面的地址是固定的，可以但看如下的XML:

<Layerqueryable="1">
    <Name>spearfish</Name>
    <Title>spearfish</Title>
    <Abstract>Layer-Group type layer: spearfish</Abstract>
    <CRS>EPSG:26713</CRS>
    <EX_GeographicBoundingBox>
    <westBoundLongitude>-103.87791475407893</westBoundLongitude>
    <eastBoundLongitude>-103.62278893469492</eastBoundLongitude>
    <southBoundLatitude>44.37246687108142</southBoundLatitude>
    <northBoundLatitude>44.50235105543566</northBoundLatitude>
    </EX_GeographicBoundingBox>
    <BoundingBoxCRS="EPSG:26713"minx="589425.9342365642"miny="4913959.224611808"maxx="609518.6719560538"maxy="4928082.949945881"/>
    </Layer>
    <Layerqueryable="1">
    <Name>tasmania</Name>
    <Title>tasmania</Title>
    <Abstract>Layer-Group type layer: tasmania</Abstract>
    <CRS>EPSG:4326</CRS>
    <EX_GeographicBoundingBox>
    <westBoundLongitude>143.83482400000003</westBoundLongitude>
    <eastBoundLongitude>148.47914100000003</eastBoundLongitude>
    <southBoundLatitude>-43.648056</southBoundLatitude>
    <northBoundLatitude>-39.573891</northBoundLatitude>
    </EX_GeographicBoundingBox>
    <BoundingBoxCRS="EPSG:4326"minx="-43.648056"miny="143.83482400000003"maxx="-39.573891"maxy="148.47914100000003"/>
    </Layer>
    <Layerqueryable="1">
    <Name>tiger-ny</Name>
    <Title>tiger-ny</Title>
    <Abstract>Layer-Group type layer: tiger-ny</Abstract>
    <CRS>EPSG:4326</CRS>
    <EX_GeographicBoundingBox>
    <westBoundLongitude>-74.047185</westBoundLongitude>
    <eastBoundLongitude>-73.907005</eastBoundLongitude>
    <southBoundLatitude>40.679648</southBoundLatitude>
    <northBoundLatitude>40.882078</northBoundLatitude>
    </EX_GeographicBoundingBox>
    <BoundingBoxCRS="EPSG:4326"minx="40.679648"miny="-74.047185"maxx="40.882078"maxy="-73.907005"/>
    </Layer>
    <Layerqueryable="1">
    <Name>省界_region</Name>
    <Title>省界_region</Title>
    <Abstract/>
    <KeywordList>
    <Keyword>features</Keyword>
    <Keyword>省界_region</Keyword>
    </KeywordList>
    <CRS>EPSG:4326</CRS>
    <CRS>CRS:84</CRS>
    <EX_GeographicBoundingBox>
    <westBoundLongitude>73.441277</westBoundLongitude>
    <eastBoundLongitude>135.08693</eastBoundLongitude>
    <southBoundLatitude>18.159829</southBoundLatitude>
    <northBoundLatitude>53.561771</northBoundLatitude>
    </EX_GeographicBoundingBox>
    <BoundingBoxCRS="CRS:84"minx="73.441277"miny="18.159829"maxx="135.08693"maxy="53.561771"/>
    <BoundingBoxCRS="EPSG:4326"minx="18.159829"miny="73.441277"maxx="53.561771"maxy="135.08693"/>
    <Style>
    <Name>polygon_x</Name>
    <Title>Default Polygon</Title>
    <Abstract>A sample style that draws a polygon</Abstract>
    <LegendURLwidth="20"height="20">
    <Format>image/png</Format>
    <OnlineResourcexmlns:xlink="http://www.w3.org/1999/xlink"xlink:type="simple"xlink:href="http://localhost:8080/geoserver/cite/ows?service=WMS&request=GetLegendGraphic&format=image%2Fpng&width=20&height=20&layer=%3F%3F_region"/>
    </LegendURL>
    </Style>
    </Layer>

里面的每一个Layer节点都是一个WMS图层。

## 2、例子 ##

package gov.nasa.worldwindx.v5cn;
     
    import gov.nasa.worldwind.avlist.AVKey;
    import gov.nasa.worldwind.avlist.AVList;
    import gov.nasa.worldwind.avlist.AVListImpl;
    import gov.nasa.worldwind.ogc.wms.WMSCapabilities;
    import gov.nasa.worldwind.wms.WMSTiledImageLayer;
    import gov.nasa.worldwindx.examples.ApplicationTemplate;
     
    import java.net.URI;
    import java.net.URISyntaxException;
     
    public class WMSLayerTest extends ApplicationTemplate {
        public static class AppFrame extends ApplicationTemplate.AppFrame{
     
            private static final long serialVersionUID = 1L;
     
            public AppFrame(){
                try {
                    //请求地图的URL
                    String uri = "http://127.0.0.1:8080/geoserver/PostGIS/wms";
                    WMSCapabilities caps;
                    URI serverURI = new URI(uri);
     
                    //获得WMSCapabilities对象
                    caps = WMSCapabilities.retrieve(serverURI);
                    //解析WMSCapabilities数据
                    caps.parse();
     
                    AVList params = new AVListImpl();
     
                    //图层的名称
                    params.setValue(AVKey.LAYER_NAMES, "planet_osm_line");
                    //地图服务的协议，这里是OGC:WMS
                    params.setValue(AVKey.SERVICE_NAME, "OGC:WMS");
                    //获得地图的uri，也就是上面定义的uri
                    params.setValue(AVKey.GET_MAP_URL, uri);
                    //在本地缓存文件的名称
                    params.setValue(AVKey.DATA_CACHE_NAME, "planet_osm_line");
                    params.setValue(AVKey.TILE_URL_BUILDER, new WMSTiledImageLayer.URLBuilder(params));
     
                    WMSTiledImageLayer imageLayer = new WMSTiledImageLayer(caps,params);
                    //图层名称
                    imageLayer.setName("planet_osm_line");
                    imageLayer.setEnabled(true);
                    //图层的透明度
                    imageLayer.setOpacity(1);
                    //图层的最大显示高度
                    imageLayer.setMaxActiveAltitude(33500000);
                    getWwd().getModel().getLayers().add(imageLayer);
                    getLayerPanel().update(getWwd());
     
                } catch (URISyntaxException e) {
                    e.printStackTrace();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
     
        }
    public static void main(String[] args) {
            ApplicationTemplate.start("WMS图层", WMSLayerTest.AppFrame.class);
        }
    }

请求的URL就是GeoServer中点击【OpenLayers】中的路径：  
  
![v5-siv_2Fimages_2F2_2F1.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3AfZToL_2BoR_2FhhTyh3cuzAjNlxTKD4_3D][]

![v5-siv_2Fimages_2F2_2F2.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3AuOWKoICRn2sz_2FBy0rClgZ9yMS_2BE_3D][]

图层名称就是定义发布服务是的名称，可以在GeoServer中找到。

![v5-siv_2Fimages_2F2_2F3.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3Atz1EgNlo2UsJigX87WeZcj_2Bwa4E_3D][]

地图协议这里是OGC:WMS。

本地缓存文件的名称，就是WorldWind在本地缓存切片的文件夹名称，Win7可以在C盘的ProgramData中的WorldWindData中找到，ProgramData是一个隐藏文件。

![v5-siv_2Fimages_2F2_2F4.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3A2909CP40wt9bOgu1qPO90t0ItrY_3D][]

运行程序就可以看到发布的图层已经可以加载了。效果如下：

![v5-siv_2Fimages_2F2_2F5.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3AmVYQtp3suiMvi4TbBov3kBn5Mrc_3D][]

[http_www.v5cn.cn_p_171]: http://www.v5cn.cn/?p=171
[v5-siv_2Fimages_2F2_2F1.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3AfZToL_2BoR_2FhhTyh3cuzAjNlxTKD4_3D]: http://bcs.duapp.com/v5-siv%2Fimages%2F2%2F1.png?sign=MBO%3AGebwejy5VRNHKGGrgD2krimo%3AfZToL%2BoR%2FhhTyh3cuzAjNlxTKD4%3D
[v5-siv_2Fimages_2F2_2F2.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3AuOWKoICRn2sz_2FBy0rClgZ9yMS_2BE_3D]: http://bcs.duapp.com/v5-siv%2Fimages%2F2%2F2.png?sign=MBO%3AGebwejy5VRNHKGGrgD2krimo%3AuOWKoICRn2sz%2FBy0rClgZ9yMS%2BE%3D
[v5-siv_2Fimages_2F2_2F3.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3Atz1EgNlo2UsJigX87WeZcj_2Bwa4E_3D]: http://bcs.duapp.com/v5-siv%2Fimages%2F2%2F3.png?sign=MBO%3AGebwejy5VRNHKGGrgD2krimo%3Atz1EgNlo2UsJigX87WeZcj%2Bwa4E%3D
[v5-siv_2Fimages_2F2_2F4.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3A2909CP40wt9bOgu1qPO90t0ItrY_3D]: http://bcs.duapp.com/v5-siv%2Fimages%2F2%2F4.png?sign=MBO%3AGebwejy5VRNHKGGrgD2krimo%3A2909CP40wt9bOgu1qPO90t0ItrY%3D
[v5-siv_2Fimages_2F2_2F5.png_sign_MBO_3AGebwejy5VRNHKGGrgD2krimo_3AmVYQtp3suiMvi4TbBov3kBn5Mrc_3D]: http://bcs.duapp.com/v5-siv%2Fimages%2F2%2F5.png?sign=MBO%3AGebwejy5VRNHKGGrgD2krimo%3AmVYQtp3suiMvi4TbBov3kBn5Mrc%3D