<Map srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
    <Parameters>
        <Parameter name="sizes">256,256</Parameter>
    </Parameters>

    <Style name="style">
        <Rule>
            <MarkersSymbolizer allow-overlap="true" stroke-width="0" fill="darkorange" ignore-placement="true"/>
            <LineSymbolizer stroke="#ff0000" stroke-width="2"/>
        </Rule>
    </Style>

    <Layer name="geom-collection" srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
        <StyleName>style</StyleName>
        <Datasource>
            <Parameter name="type">geojson</Parameter>
            <Parameter name="inline">
{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {},
      "geometry": {
        "type": "GeometryCollection",
        "geometries": [
          {
            "type": "MultiPoint",
            "coordinates": [ [5,0], [0,5], [1,2.5], [4,2.5] ]
          },
          {
            "type": "LineString",
            "coordinates": [
              [
                0,
                5
              ],
              [
                5,
                0
              ]
            ]
          }
        ]
      }
    }
  ]
}
</Parameter>
        </Datasource>
    </Layer>
</Map>