Ejemplo n.º 1
0
  /**
   * Build an appropriate <code>Geometry</code>, <code>MultiGeometry</code>, or <code>
   * GeometryCollection</code> to contain the <code>Geometry</code>s in it. For example:<br>
   *
   * <ul>
   *   <li>If <code>geomList</code> contains a single <code>Polygon</code>, the <code>Polygon</code>
   *       is returned.
   *   <li>If <code>geomList</code> contains several <code>Polygon</code>s, a <code>MultiPolygon
   *       </code> is returned.
   *   <li>If <code>geomList</code> contains some <code>Polygon</code>s and some <code>LineString
   *       </code>s, a <code>GeometryCollection</code> is returned.
   *   <li>If <code>geomList</code> is empty, an empty <code>GeometryCollection</code> is returned
   * </ul>
   *
   * Note that this method does not "flatten" Geometries in the input, and hence if any
   * MultiGeometries are contained in the input a GeometryCollection containing them will be
   * returned.
   *
   * @param geomList the <code>Geometry</code>s to combine
   * @return a <code>Geometry</code> of the "smallest", "most type-specific" class that can contain
   *     the elements of <code>geomList</code> .
   */
  public Geometry buildGeometry(Collection geomList) {

    /** Determine some facts about the geometries in the list */
    Class geomClass = null;
    boolean isHeterogeneous = false;
    boolean hasGeometryCollection = false;
    for (Iterator i = geomList.iterator(); i.hasNext(); ) {
      Geometry geom = (Geometry) i.next();
      Class partClass = geom.getClass();
      if (geomClass == null) {
        geomClass = partClass;
      }
      if (partClass != geomClass) {
        isHeterogeneous = true;
      }
      if (geom instanceof GeometryCollection) hasGeometryCollection = true;
    }

    /** Now construct an appropriate geometry to return */
    // for the empty geometry, return an empty GeometryCollection
    if (geomClass == null) {
      return createGeometryCollection(null);
    }
    if (isHeterogeneous || hasGeometryCollection) {
      return createGeometryCollection(toGeometryArray(geomList));
    }
    // at this point we know the collection is hetereogenous.
    // Determine the type of the result from the first Geometry in the list
    // this should always return a geometry, since otherwise an empty collection would have already
    // been returned
    Geometry geom0 = (Geometry) geomList.iterator().next();
    boolean isCollection = geomList.size() > 1;
    if (isCollection) {
      if (geom0 instanceof Polygon) {
        return createMultiPolygon(toPolygonArray(geomList));
      } else if (geom0 instanceof LineString) {
        return createMultiLineString(toLineStringArray(geomList));
      } else if (geom0 instanceof Point) {
        return createMultiPoint(toPointArray(geomList));
      }
      Assert.shouldNeverReachHere("Unhandled class: " + geom0.getClass().getName());
    }
    return geom0;
  }
Ejemplo n.º 2
0
 public static Point createPointFromInternalCoord(Coordinate coord, Geometry exemplar) {
   exemplar.getPrecisionModel().makePrecise(coord);
   return exemplar.getFactory().createPoint(coord);
 }