Class GMLWriter


  • public class GMLWriter
    extends java.lang.Object
    Writes Geometrys as XML fragments in GML2 format. Allows specifying the XML prefix, namespace and srsName of the emitted GML. Also allows adding custom root elements to support GML extensions such as KML. With appropriate settings for prefix (none) and custom root elements this class can be used to write out geometry in KML format.

    An example of the output that can be generated is:

     <gml:LineString xmlns:gml='http://www.opengis.net/gml' srsName='foo'>
       <gml:coordinates>
         6.03,8.17 7.697,6.959 8.333,5.0 7.697,3.041 6.03,1.83 3.97,1.83 2.303,3.041 1.667,5.0 2.303,6.959 3.97,8.17 
       </gml:coordinates>
     </gml:LineString>
     

    This class does not rely on any external XML libraries.

    • Field Detail

      • startingIndentIndex

        private int startingIndentIndex
      • maxCoordinatesPerLine

        private int maxCoordinatesPerLine
      • emitNamespace

        private boolean emitNamespace
      • isRootTag

        private boolean isRootTag
      • prefix

        private java.lang.String prefix
      • namespace

        private java.lang.String namespace
      • srsName

        private java.lang.String srsName
      • customElements

        private java.lang.String[] customElements
      • coordinateSeparator

        private static final java.lang.String coordinateSeparator
        See Also:
        Constant Field Values
    • Constructor Detail

      • GMLWriter

        public GMLWriter()
        Creates a writer which outputs GML with default settings. The defaults are:
        • the namespace prefix is gml:
        • no namespace prefix declaration is written
        • no srsName attribute is written
      • GMLWriter

        public GMLWriter​(boolean emitNamespace)
        Creates a writer which may emit the GML namespace prefix declaration in the geometry root element.
        Parameters:
        emitNamespace - true if the GML namespace prefix declaration should be written in the geometry root element
    • Method Detail

      • setPrefix

        public void setPrefix​(java.lang.String prefix)
        Specifies the namespace prefix to write on each GML tag. A null or blank prefix may be used to indicate no prefix.

        The default is to write gml: as the namespace prefix.

        Parameters:
        prefix - the namespace prefix to use (null or blank if none)
      • setSrsName

        public void setSrsName​(java.lang.String srsName)
        Sets the value of the srsName attribute to be written into the root geometry tag. If the value is null or blank no srsName attribute will be written. The provided value must be a valid XML attribute value - it will not be XML-escaped.

        The default is not to write the srsName attribute.

        Parameters:
        srsName - the srsName attribute value
      • setNamespace

        public void setNamespace​(boolean emitNamespace)
        Determines whether a GML namespace declaration will be written in the opening tag of geometries. Useful in XML-aware environments which parse the geometries before use, such as XSLT.
        Parameters:
        emitNamespace - true if the GML namespace prefix declaration should be written in the root geometry element
      • setCustomElements

        public void setCustomElements​(java.lang.String[] customElements)
        Specifies a list of custom elements which are written after the opening tag of the root element. The text contained in the string sequence should form valid XML markup. The specified strings are written one per line immediately after the root geometry tag line.

        For instance, this is useful for adding KML-specific geometry parameters such as <extrude>

        Parameters:
        customElements - a list of the custom element strings, or null if none
      • setStartingIndentIndex

        public void setStartingIndentIndex​(int indent)
        Sets the starting column index for pretty printing
        Parameters:
        indent -
      • setMaxCoordinatesPerLine

        public void setMaxCoordinatesPerLine​(int num)
        Sets the number of coordinates printed per line.
        Parameters:
        num -
      • write

        public java.lang.String write​(Geometry geom)
        Writes a Geometry in GML2 format to a String.
        Parameters:
        geom -
        Returns:
        String GML2 Encoded Geometry
      • write

        public void write​(Geometry geom,
                          java.io.Writer writer)
                   throws java.io.IOException
        Writes a Geometry in GML2 format into a Writer.
        Parameters:
        geom - Geometry to encode
        writer - Stream to encode to.
        Throws:
        java.io.IOException
      • write

        private void write​(Geometry geom,
                           java.io.Writer writer,
                           int level)
                    throws java.io.IOException
        Throws:
        java.io.IOException
      • writePoint

        private void writePoint​(Point p,
                                java.io.Writer writer,
                                int level)
                         throws java.io.IOException
        Throws:
        java.io.IOException
      • writeLineString

        private void writeLineString​(LineString ls,
                                     java.io.Writer writer,
                                     int level)
                              throws java.io.IOException
        Throws:
        java.io.IOException
      • writeLinearRing

        private void writeLinearRing​(LinearRing lr,
                                     java.io.Writer writer,
                                     int level)
                              throws java.io.IOException
        Throws:
        java.io.IOException
      • writePolygon

        private void writePolygon​(Polygon p,
                                  java.io.Writer writer,
                                  int level)
                           throws java.io.IOException
        Throws:
        java.io.IOException
      • writeMultiPoint

        private void writeMultiPoint​(MultiPoint mp,
                                     java.io.Writer writer,
                                     int level)
                              throws java.io.IOException
        Throws:
        java.io.IOException
      • writeMultiLineString

        private void writeMultiLineString​(MultiLineString mls,
                                          java.io.Writer writer,
                                          int level)
                                   throws java.io.IOException
        Throws:
        java.io.IOException
      • writeMultiPolygon

        private void writeMultiPolygon​(MultiPolygon mp,
                                       java.io.Writer writer,
                                       int level)
                                throws java.io.IOException
        Throws:
        java.io.IOException
      • writeGeometryCollection

        private void writeGeometryCollection​(GeometryCollection gc,
                                             java.io.Writer writer,
                                             int level)
                                      throws java.io.IOException
        Throws:
        java.io.IOException
      • write

        private void write​(Coordinate[] coords,
                           java.io.Writer writer,
                           int level)
                    throws java.io.IOException
        Takes a list of coordinates and converts it to GML.
        2d and 3d aware.
        Parameters:
        coords - array of coordinates
        Throws:
        java.io.IOException
      • startLine

        private void startLine​(int level,
                               java.io.Writer writer)
                        throws java.io.IOException
        Throws:
        java.io.IOException
      • startGeomTag

        private void startGeomTag​(java.lang.String geometryName,
                                  Geometry g,
                                  java.io.Writer writer)
                           throws java.io.IOException
        Throws:
        java.io.IOException
      • writeAttributes

        private void writeAttributes​(Geometry geom,
                                     java.io.Writer writer)
                              throws java.io.IOException
        Throws:
        java.io.IOException
      • writeCustomElements

        private void writeCustomElements​(Geometry geom,
                                         java.io.Writer writer)
                                  throws java.io.IOException
        Throws:
        java.io.IOException
      • endGeomTag

        private void endGeomTag​(java.lang.String geometryName,
                                java.io.Writer writer)
                         throws java.io.IOException
        Throws:
        java.io.IOException
      • prefix

        private java.lang.String prefix()