Empty WKT Strings (#1162) (#1237)

* read ahead and check if empty string, if so, return empty geom * specifically force toStrings to return geom with EMPTY string * Tests for empty WKT parsing * Check if bbox exists before reaching into it * WKT writer specifically write EMPTY string * isEmpty for Geometry interface, do not simplify if empty
GCRC · Jul 24, 2024 · 2baff93 · 2baff93
1 parent d3a7871
commit 2baff93
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Showing 13 changed files with 321 additions and 126 deletions.
diff --git a/...java/ca/carleton/gcrc/couch/onUpload/simplifyGeoms/GeometrySimplificationProcessImpl.java b/...java/ca/carleton/gcrc/couch/onUpload/simplifyGeoms/GeometrySimplificationProcessImpl.java
@@ -38,6 +38,9 @@ public GeometrySimplificationReport simplifyGeometry(Geometry geometry) throws E
 
 			if( geometry instanceof Point ){
 				// Do not simplify points
+			} 
+			else if (geometry.isEmpty()) {
+				// Don't simplify what doesn't exist
 			} else {
 				Geometry lastGeometry = null;
 				for(Double resolution : resolutions){

diff --git a/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/Geometry.java b/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/Geometry.java
@@ -7,6 +7,8 @@ public interface Geometry {
 	BoundingBox getBoundingBox();
 
 	void extendBoundingBox(BoundingBox boundingBox);
+
+	boolean isEmpty();
 
 	/**
 	 * Unravels all the geometry collections and saves the basic

diff --git a/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/GeometryCollection.java b/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/GeometryCollection.java
@@ -35,6 +35,12 @@ public void addGeometry(Geometry geometry){
 	public String toString(){
 		StringWriter sw = new StringWriter();
 		PrintWriter pw = new PrintWriter(sw);
+
+		if (isEmpty()) {
+			pw.print("GEOMETRYCOLLECTION EMPTY");
+			pw.flush();
+			return sw.toString();
+		}
 
 		pw.print("GEOMETRYCOLLECTION(");
 
@@ -68,4 +74,9 @@ public void accumulateBasicGeometries(Collection<Geometry> geometries) {
 			geometry.accumulateBasicGeometries(geometries);
 		}
 	}
+
+	@Override
+	public boolean isEmpty() {
+		return (getGeometries().size() == 0);
+	}
 }
diff --git a/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/LineString.java b/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/LineString.java
@@ -29,6 +29,12 @@ public void addPoint(Point point){
 	public String toString(){
 		StringWriter sw = new StringWriter();
 		PrintWriter pw = new PrintWriter(sw);
+
+		if (isEmpty()) {
+			pw.print("LINESTRING EMPTY");
+			pw.flush();
+			return sw.toString();
+		}
 
 		pw.print("LINESTRING(");
 
@@ -69,4 +75,9 @@ public void extendBoundingBox(BoundingBox boundingBox) {
 	public void accumulateBasicGeometries(Collection<Geometry> geometries) {
 		geometries.add(this);
 	}
+
+	@Override
+	public boolean isEmpty() {
+		return (getPoints().size() == 0);
+	}
 }
diff --git a/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/MultiLineString.java b/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/MultiLineString.java
@@ -41,6 +41,12 @@ public void addLineString(LineString lineString){
 	public String toString(){
 		StringWriter sw = new StringWriter();
 		PrintWriter pw = new PrintWriter(sw);
+
+		if (isEmpty()) {
+			pw.print("MULTILINESTRING EMPTY");
+			pw.flush();
+			return sw.toString();
+		}
 
 		pw.print("MULTILINESTRING(");
 
@@ -94,4 +100,9 @@ public void accumulateBasicGeometries(Collection<Geometry> geometries) {
 			lineString.accumulateBasicGeometries(geometries);
 		}
 	}
+
+	@Override
+	public boolean isEmpty() {
+		return (getLineStrings().size() == 0);
+	}
 }
diff --git a/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/MultiPoint.java b/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/MultiPoint.java
@@ -41,6 +41,12 @@ public void addPoint(Point point){
 	public String toString(){
 		StringWriter sw = new StringWriter();
 		PrintWriter pw = new PrintWriter(sw);
+
+		if (isEmpty()) {
+			pw.print("MULTIPOINT EMPTY");
+			pw.flush();
+			return sw.toString();
+		}
 
 		pw.print("MULTIPOINT(");
 
@@ -85,4 +91,9 @@ public void accumulateBasicGeometries(Collection<Geometry> geometries) {
 			point.accumulateBasicGeometries(geometries);
 		}
 	}
+
+	@Override
+	public boolean isEmpty() {
+		return (getPoints().size() == 0);
+	}
 }
diff --git a/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/MultiPolygon.java b/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/MultiPolygon.java
@@ -41,6 +41,12 @@ public void addPolygon(Polygon polygon){
 	public String toString(){
 		StringWriter sw = new StringWriter();
 		PrintWriter pw = new PrintWriter(sw);
+
+		if (isEmpty()) {
+			pw.print("MULTIPOLYGON EMPTY");
+			pw.flush();
+			return sw.toString();
+		}
 
 		pw.print("MULTIPOLYGON(");
 
@@ -107,4 +113,9 @@ public void accumulateBasicGeometries(Collection<Geometry> geometries) {
 			polygon.accumulateBasicGeometries(geometries);
 		}
 	}
+
+	@Override
+	public boolean isEmpty() {
+		return (getPolygons().size() == 0);
+	}
 }
diff --git a/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/Point.java b/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/Point.java
@@ -69,6 +69,12 @@ public Double getZ(){
 	public String toString(){
 		StringWriter sw = new StringWriter();
 		PrintWriter pw = new PrintWriter(sw);
+
+		if (isEmpty()) {
+			pw.print("POINT EMPTY");
+			pw.flush();
+			return sw.toString();
+		}
 
 		pw.print("POINT(");
 
@@ -98,4 +104,9 @@ public void extendBoundingBox(BoundingBox boundingBox) {
 	public void accumulateBasicGeometries(Collection<Geometry> geometries) {
 		geometries.add(this);
 	}
+
+	@Override
+	public boolean isEmpty() {
+		return (getPositions().size() == 0);
+	}
 }
diff --git a/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/Polygon.java b/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/Polygon.java
@@ -29,6 +29,12 @@ public void addLinearRing(LineString linearRing){
 	public String toString(){
 		StringWriter sw = new StringWriter();
 		PrintWriter pw = new PrintWriter(sw);
+
+		if (isEmpty()) {
+			pw.print("POLYGON EMPTY");
+			pw.flush();
+			return sw.toString();
+		}
 
 		pw.print("POLYGON(");
 
@@ -80,4 +86,9 @@ public void extendBoundingBox(BoundingBox boundingBox) {
 	public void accumulateBasicGeometries(Collection<Geometry> geometries) {
 		geometries.add(this);
 	}
+
+	@Override
+	public boolean isEmpty() {
+		return (getLinearRings().size() == 0);
+	}
 }
diff --git a/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/wkt/WktParser.java b/nunaliit2-geom/src/main/java/ca/carleton/gcrc/geom/wkt/WktParser.java
@@ -34,14 +34,18 @@ public Geometry parseWkt(Reader reader) throws Exception {
 		BufferedReader bufReader = new BufferedReader(reader);
 		return parseGeometry(bufReader);
 	}
+
+	private boolean isWKTEmpty(BufferedReader br) throws Exception {
+		String geomData = readIdentifier(br);
+		return geomData.equalsIgnoreCase("empty");
+	}
 
 	private Geometry parseGeometry(BufferedReader bufReader) throws Exception {
 
 		Geometry geometry = null;
 		try {
 			skipWhiteSpaces(bufReader);
 			String identifier = readIdentifier(bufReader);
-
 			if( "point".equalsIgnoreCase(identifier) ) {
 				geometry = parsePoint(bufReader);
 
@@ -281,6 +285,11 @@ private List<Number> parsePositions(BufferedReader br) throws Exception {
 	private Point parsePoint(BufferedReader br) throws Exception {
 
 		skipWhiteSpaces(br);
+
+		if (isWKTEmpty(br)) {
+			return new Point();
+		}
+
 		popLeftParen(br);
 
 		List<Number> positions = parsePositions(br);
@@ -299,6 +308,11 @@ private LineString parseLineString(BufferedReader br) throws Exception {
 		LineString lineString = new LineString();
 
 		skipWhiteSpaces(br);
+
+		if (isWKTEmpty(br)) {
+			return lineString;
+		}
+
 		popLeftParen(br);
 
 		// Accumulate points
@@ -329,6 +343,11 @@ private Polygon parsePolygon(BufferedReader br) throws Exception {
 		Polygon polygon = new Polygon();
 
 		skipWhiteSpaces(br);
+
+		if (isWKTEmpty(br)) {
+			return polygon;
+		}
+
 		popLeftParen(br);
 
 		LineString ls = parseLineString(br);
@@ -351,6 +370,11 @@ private MultiPoint parseMultiPoint(BufferedReader br) throws Exception {
 		MultiPoint multiPoint = new MultiPoint();
 
 		skipWhiteSpaces(br);
+
+		if (isWKTEmpty(br)) {
+			return multiPoint;
+		}
+
 		popLeftParen(br);
 
 		boolean done = false;
@@ -386,6 +410,11 @@ private MultiLineString parseMultiLineString(BufferedReader br) throws Exception
 		MultiLineString multiLineString = new MultiLineString();
 
 		skipWhiteSpaces(br);
+
+		if (isWKTEmpty(br)) {
+			return multiLineString;
+		}
+
 		popLeftParen(br);
 
 		boolean done = false;
@@ -412,6 +441,11 @@ private MultiPolygon parseMultiPolygon(BufferedReader br) throws Exception {
 		MultiPolygon multiPolygon = new MultiPolygon();
 
 		skipWhiteSpaces(br);
+
+		if (isWKTEmpty(br)) {
+			return multiPolygon;
+		}
+
 		popLeftParen(br);
 
 		boolean done = false;
@@ -438,6 +472,11 @@ private GeometryCollection parseGeometryCollection(BufferedReader br) throws Exc
 		GeometryCollection geometryCollection = new GeometryCollection();
 
 		skipWhiteSpaces(br);
+
+		if (isWKTEmpty(br)) {
+			return geometryCollection;
+		}
+
 		popLeftParen(br);
 
 		boolean done = false;