org.geolatte.geom.codec.PostgisWktDecoder Maven / Gradle / Ivy
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/*
* This file is part of the GeoLatte project.
*
* GeoLatte is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GeoLatte is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with GeoLatte. If not, see This class is not thread-safe
*
* @author Karel Maesen, Geovise BVBA, 2011
*/
class PostgisWktDecoder extends AbstractWktDecoder> implements WktDecoder {
private final static PostgisWktVariant WKT_GEOM_TOKENS = new PostgisWktVariant();
private final static Pattern SRID_RE = Pattern.compile("^SRID=(.*);", Pattern.CASE_INSENSITIVE);
private String wktString;
private CoordinateReferenceSystem crs;
public PostgisWktDecoder() {
super(WKT_GEOM_TOKENS);
}
protected PostgisWktDecoder(WktVariant wktVariant) {
super(wktVariant);
}
public Geometry decode(String wkt) {
return decode(wkt, (CoordinateReferenceSystem)null);
}
@Override
@SuppressWarnings("unchecked")
public Geometry
decode(String wkt, CoordinateReferenceSystem
crs) {
if (wkt == null || wkt.isEmpty()) {
throw new WktDecodeException("Null or empty string cannot be decoded into a geometry");
}
prepare(wkt, crs);
initializeTokenizer(crs != null);
return (Geometry
)decodeGeometry(this.crs);
}
/**
* The instance fields wktString and crsId are initialized prior to decoding. For postgis EWKT that entails
* extracting the SRID prefix (if any) from the WKT string.
*
* @param wkt the WKT representation
*/
private
void prepare(String wkt, CoordinateReferenceSystem
crs) {
Matcher matcher = SRID_RE.matcher(wkt);
if (matcher.find()) {
int srid = Integer.parseInt(matcher.group(1));
this.crs = crs != null? crs : CrsRegistry.getCoordinateReferenceSystemForEPSG(srid, CoordinateReferenceSystems.PROJECTED_2D_METER);
wktString = wkt.substring(matcher.end());
} else {
this.crs = crs != null ? crs : CoordinateReferenceSystems.PROJECTED_2D_METER;
wktString = wkt;
}
}
private void initializeTokenizer(boolean forceToCRS) {
setTokenizer(new WktTokenizer(wktString, getWktVariant(), crs, forceToCRS));
nextToken();
}
private
Geometry
decodeGeometry(CoordinateReferenceSystem
crs) {
if (!(currentToken instanceof WktGeometryToken)) {
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
GeometryType type = ((WktGeometryToken) currentToken).getType();
nextToken();
switch (type) {
case POINT:
return decodePointText(crs);
case LINESTRING:
return decodeLineStringText(crs);
case POLYGON:
return decodePolygonText(crs);
case GEOMETRYCOLLECTION:
return decodeGeometryCollection(crs);
case MULTIPOINT:
return decodeMultiPoint(crs);
case MULTILINESTRING:
return decodeMultiLineString(crs);
case MULTIPOLYGON:
return decodeMultiPolygon(crs);
}
throw new WktDecodeException("Unsupported geometry type in Wkt: " + type);
}
private
MultiPolygon
decodeMultiPolygon(CoordinateReferenceSystem
crs) {
if (matchesOpenList()) {
List> polygons = new ArrayList>();
while (!matchesCloseList()) {
polygons.add(decodePolygonText(crs));
matchesElementSeparator();
}
return mkMultiPolygon(polygons);
}
if (matchesEmptyToken()) {
return new MultiPolygon(crs);
}
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
private
Geometry
decodeMultiLineString(CoordinateReferenceSystem
crs) {
if (matchesOpenList()) {
List> lineStrings = new ArrayList>();
while (!matchesCloseList()) {
lineStrings.add(decodeLineStringText(crs));
matchesElementSeparator();
}
return mkMultiLineString(lineStrings);
}
if (matchesEmptyToken()) {
return new MultiLineString(crs);
}
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
private
Geometry
decodeMultiPoint(CoordinateReferenceSystem
crs) {
if (matchesOpenList()) {
List> points = new ArrayList>();
//this handles the case of the non-compliant MultiPoints in Postgis (e.g.
// MULTIPOINT(10 10, 12 13) rather than MULTIPOINT((10 20), (30 40))
if (currentToken instanceof WktPointSequenceToken) {
PositionSequence positionSequence = ((WktPointSequenceToken
) currentToken).getPositions();
CoordinateReferenceSystem
tcrs = ((WktPointSequenceToken
) currentToken).getCoordinateReferenceSystem();
for (P p : positionSequence) {
points.add(new Point
(p, tcrs));
}
nextToken();
}
while (!matchesCloseList()) {
points.add(decodePointText(crs));
matchesElementSeparator();
}
return mkMultiPoint(points);
}
if (matchesEmptyToken()) {
return new MultiPoint
(crs);
}
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
private
GeometryCollection> decodeGeometryCollection(CoordinateReferenceSystem crs) {
if (matchesOpenList()) {
List> geometries = new ArrayList>();
while (!matchesCloseList()) {
geometries.add(decodeGeometry(crs));
matchesElementSeparator();
}
return mkGeometryCollection(geometries);
}
if (matchesEmptyToken()) {
return new GeometryCollection>(crs);
}
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
private Polygon
decodePolygonText(CoordinateReferenceSystem
crs) {
if (matchesOpenList()) {
List> rings = new ArrayList>();
while (!matchesCloseList()) {
LinearRing ring = decodeLinearRingText(crs);
if (ring.isEmpty()) {
throw new WktDecodeException("Empty ring found in polygon" +
"Wkt: " + wktString);
}
rings.add(ring);
matchesElementSeparator();
}
return mkPolygon(rings);
}
if (matchesEmptyToken()) {
return new Polygon(crs);
}
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
private
LinearRing
decodeLinearRingText(CoordinateReferenceSystem
crs) {
try {
WktPointSequenceToken
token = decodePointSequence(crs);
if (token == null) throw new WktDecodeException("No Linear Ring when expected");
return new LinearRing
(token.getPositions(), token.getCoordinateReferenceSystem());
} catch (IllegalArgumentException ex) {
throw new WktDecodeException(ex.getMessage());
}
}
private
LineString
decodeLineStringText(CoordinateReferenceSystem
crs) {
WktPointSequenceToken
token = decodePointSequence(crs);
if (token != null) {
PositionSequence
positionSequence = token.getPositions();
CoordinateReferenceSystem
tcrs = token.getCoordinateReferenceSystem();
return new LineString
(positionSequence, tcrs);
}
if (matchesEmptyToken()) {
return new LineString
(crs);
}
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
private
Point
decodePointText(CoordinateReferenceSystem
crs) {
WktPointSequenceToken
token = decodePointSequence(crs);
if (token != null) {
PositionSequence
positionSequence = token.getPositions();
CoordinateReferenceSystem
tcrs = token.getCoordinateReferenceSystem();
return new Point
(positionSequence, tcrs);
}
if (matchesEmptyToken()) {
return new Point
(crs);
}
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
private boolean matchesEmptyToken() {
if (currentToken == WKT_GEOM_TOKENS.getEmpty()) {
nextToken();
return true;
}
return false;
}
private
WktPointSequenceToken
decodePointSequence(CoordinateReferenceSystem
forceCrs) {
WktPointSequenceToken
token = null;
if (matchesOpenList()) {
if (currentToken instanceof WktPointSequenceToken) {
token = (WktPointSequenceToken
) currentToken;
nextToken();
} else {
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
if (!matchesCloseList()) {
throw new WktDecodeException(buildWrongSymbolAtPositionMsg());
}
}
return token;
}
private String buildWrongSymbolAtPositionMsg() {
return "Wrong symbol at position: " + getTokenizerPosition() + " in Wkt: " + wktString;
}
}