Merge pull request #1166 from katzyn/EWKT

Add SRID support to EWKT format

h2/src/docsrc/help/help.csv

@@ -2895,9 +2895,10 @@ ENUM('clubs', 'diamonds', 'hearts', 'spades')
 GEOMETRY
 ","
 A spatial geometry type, based on the ""org.locationtech.jts"" library.
-Normally represented in textual format using the WKT (well known text) format.
+May be represented in textual format using the WKT (well-known text) or EWKT (extended well-known text) format.
+Values are stored internally in EWKB (extended well-known binary) format.
 
-Use a quoted string containing a WKT formatted string or ""PreparedStatement.setObject()"" to store values,
+Use a quoted string containing a WKT/EWKT formatted string or ""PreparedStatement.setObject()"" to store values,
 and ""ResultSet.getObject(..)"" or ""ResultSet.getString(..)"" to retrieve the values.
 ","
 GEOMETRY

h2/src/main/org/h2/value/ValueGeometry.java

@@ -100,14 +100,25 @@ public class ValueGeometry extends Value {
     /**
      * Get or create a geometry value for the given geometry.
      *
-     * @param s the WKT representation of the geometry
+     * @param s the WKT or EWKT representation of the geometry
      * @return the value
      */
     public static ValueGeometry get(String s) {
         try {
-            Geometry g = new WKTReader().read(s);
-            return get(g);
-        } catch (ParseException ex) {
+            int srid;
+            if (s.startsWith("SRID=")) {
+                int idx = s.indexOf(';', 5);
+                srid = Integer.parseInt(s.substring(5, idx));
+                s = s.substring(idx + 1);
+            } else {
+                srid = 0;
+            }
+            /*
+             * No-arg WKTReader() constructor instantiates a new GeometryFactory and a new
+             * PrecisionModel anyway, so special case for srid == 0 is not needed.
+             */
+            return get(new WKTReader(new GeometryFactory(new PrecisionModel(), srid)).read(s));
+        } catch (ParseException | StringIndexOutOfBoundsException | NumberFormatException ex) {
             throw DbException.convert(ex);
         }
     }
@@ -120,10 +131,9 @@ public class ValueGeometry extends Value {
      * @return the value
      */
     public static ValueGeometry get(String s, int srid) {
+        // This method is not used in H2, but preserved for H2GIS
         try {
-            GeometryFactory geometryFactory = new GeometryFactory(new PrecisionModel(), srid);
-            Geometry g = new WKTReader(geometryFactory).read(s);
-            return get(g);
+            return get(new WKTReader(new GeometryFactory(new PrecisionModel(), srid)).read(s));
         } catch (ParseException ex) {
             throw DbException.convert(ex);
         }
@@ -154,8 +164,25 @@ public class ValueGeometry extends Value {
     public Geometry getGeometryNoCopy() {
         if (geometry == null) {
             try {
-                int srid = 0;
-                getSRID: if (bytes.length >= 9) {
+                /*
+                 * No-arg WKBReader() constructor instantiates a new GeometryFactory and a new
+                 * PrecisionModel anyway, so special case for srid == 0 is not needed.
+                 */
+                geometry = new WKBReader(new GeometryFactory(new PrecisionModel(), getSRID())).read(bytes);
+            } catch (ParseException ex) {
+                throw DbException.convert(ex);
+            }
+        }
+        return geometry;
+    }
+
+    /**
+     * Return the SRID (Spatial Reference Identifier).
+     *
+     * @return spatial reference identifier
+     */
+    public int getSRID() {
+        if (bytes.length >= 9) {
             boolean bigEndian;
             switch (bytes[0]) {
             case 0:
@@ -165,25 +192,17 @@ public class ValueGeometry extends Value {
                 bigEndian = false;
                 break;
             default:
-                        break getSRID;
+                return 0;
             }
             if ((bytes[bigEndian ? 1 : 4] & 0x20) != 0) {
-                        srid = Bits.readInt(bytes, 5);
+                int srid = Bits.readInt(bytes, 5);
                 if (!bigEndian) {
                     srid = Integer.reverseBytes(srid);
                 }
+                return srid;
             }
         }
-                /*
-                 * No-arg WKBReader() constructor instantiates a new GeometryFactory and a new
-                 * PrecisionModel anyway, so special case for srid == 0 is not needed.
-                 */
-                geometry = new WKBReader(new GeometryFactory(new PrecisionModel(), srid)).read(bytes);
-            } catch (ParseException ex) {
-                throw DbException.convert(ex);
-            }
-        }
-        return geometry;
+        return 0;
     }
 
     /**
@@ -219,9 +238,7 @@ public class ValueGeometry extends Value {
 
     @Override
     public String getSQL() {
-        // WKT does not hold Z or SRID with JTS 1.13. As getSQL is used to
-        // export database, it should contains all object attributes. Moreover
-        // using bytes is faster than converting WKB to Geometry then to WKT.
+        // Using bytes is faster than converting EWKB to Geometry then EWKT.
         return "X'" + StringUtils.convertBytesToHex(getBytesNoCopy()) + "'::Geometry";
     }
 
@@ -233,7 +250,7 @@ public class ValueGeometry extends Value {
 
     @Override
     public String getString() {
-        return getWKT();
+        return getEWKT();
     }
 
     @Override
@@ -253,12 +270,12 @@ public class ValueGeometry extends Value {
 
     @Override
     public byte[] getBytes() {
-        return Utils.cloneByteArray(getWKB());
+        return Utils.cloneByteArray(getEWKB());
     }
 
     @Override
     public byte[] getBytesNoCopy() {
-        return getWKB();
+        return getEWKB();
     }
 
     @Override
@@ -269,12 +286,12 @@ public class ValueGeometry extends Value {
 
     @Override
     public int getDisplaySize() {
-        return getWKT().length();
+        return getEWKT().length();
     }
 
     @Override
     public int getMemory() {
-        return getWKB().length * 20 + 24;
+        return getEWKB().length * 20 + 24;
     }
 
     @Override
@@ -282,24 +299,29 @@ public class ValueGeometry extends Value {
         // The JTS library only does half-way support for 3D coordinates, so
         // their equals method only checks the first two coordinates.
         return other instanceof ValueGeometry &&
-                Arrays.equals(getWKB(), ((ValueGeometry) other).getWKB());
+                Arrays.equals(getEWKB(), ((ValueGeometry) other).getEWKB());
     }
 
     /**
-     * Get the value in Well-Known-Text format.
+     * Get the value in Extended Well-Known Text format.
      *
-     * @return the well-known-text
+     * @return the extended well-known text
      */
-    public String getWKT() {
-        return new WKTWriter(3).write(getGeometryNoCopy());
+    public String getEWKT() {
+        String wkt = new WKTWriter(3).write(getGeometryNoCopy());
+        int srid = getSRID();
+        return srid == 0
+                ? wkt
+                // "SRID=-2147483648;".length() == 17
+                : new StringBuilder(wkt.length() + 17).append("SRID=").append(srid).append(';').append(wkt).toString();
     }
 
     /**
-     * Get the value in Well-Known-Binary format.
+     * Get the value in extended Well-Known Binary format.
      *
-     * @return the well-known-binary
+     * @return the extended well-known binary
      */
-    public byte[] getWKB() {
+    public byte[] getEWKB() {
         return bytes;
     }
 

h2/src/test/org/h2/test/db/TestSpatial.java

@@ -597,8 +597,9 @@ public class TestSpatial extends TestBase {
      * Test serialization of Z and SRID values.
      */
     private void testWKB() {
-        ValueGeometry geom3d = ValueGeometry.get(
-                "POLYGON ((67 13 6, 67 18 5, 59 18 4, 59 13 6,  67 13 6))", 27572);
+        String ewkt = "SRID=27572;POLYGON ((67 13 6, 67 18 5, 59 18 4, 59 13 6, 67 13 6))";
+        ValueGeometry geom3d = ValueGeometry.get(ewkt);
+        assertEquals(ewkt, geom3d.getString());
         ValueGeometry copy = ValueGeometry.get(geom3d.getBytes());
         assertEquals(6, copy.getGeometry().getCoordinates()[0].z);
         assertEquals(5, copy.getGeometry().getCoordinates()[1].z);
@@ -606,6 +607,7 @@ public class TestSpatial extends TestBase {
         // Test SRID
         copy = ValueGeometry.get(geom3d.getBytes());
         assertEquals(27572, copy.getGeometry().getSRID());
+
         Point point = new GeometryFactory().createPoint((new Coordinate(1.1d, 1.2d)));
         // SRID 0
         checkSRID(ValueGeometry.getFromGeometry(point).getBytes(), 0);
@@ -613,11 +615,17 @@ public class TestSpatial extends TestBase {
         checkSRID(new WKBWriter(2, ByteOrderValues.BIG_ENDIAN, true).write(point), 0);
         checkSRID(new WKBWriter(2, ByteOrderValues.LITTLE_ENDIAN, false).write(point), 0);
         checkSRID(new WKBWriter(2, ByteOrderValues.LITTLE_ENDIAN, true).write(point), 0);
+        ewkt = "POINT (1.1 1.2)";
+        assertEquals(ewkt, ValueGeometry.getFromGeometry(point).getString());
+        assertEquals(ewkt, ValueGeometry.get(ewkt).getString());
         // SRID 1,000,000,000
         point.setSRID(1_000_000_000);
         checkSRID(ValueGeometry.getFromGeometry(point).getBytes(), 1_000_000_000);
         checkSRID(new WKBWriter(2, ByteOrderValues.BIG_ENDIAN, true).write(point), 1_000_000_000);
         checkSRID(new WKBWriter(2, ByteOrderValues.LITTLE_ENDIAN, true).write(point), 1_000_000_000);
+        ewkt = "SRID=1000000000;POINT (1.1 1.2)";
+        assertEquals(ewkt, ValueGeometry.getFromGeometry(point).getString());
+        assertEquals(ewkt, ValueGeometry.get(ewkt).getString());
     }
 
     private void checkSRID(byte[] bytes, int srid) {