Add a unit test plus a method to get elements from a PRJ string. Useful to parse OGC WKT2 format

Author: ebocher

docs/CHANGELOG.md

@@ -4,3 +4,4 @@
 - Remove unnecessary logger
 - Update github actions
 - Change to central portal publishing
+- Add a new method to return the elements from a PRJ string

src/main/java/org/cts/parser/prj/PrjParser.java

@@ -50,24 +50,39 @@ public PrjParser() {
     }
 
     /**
-     * Parses a WKT PRJ String into a set of parameters.
+     * Parses a WKT PRJ String into a {@code PrjElement}.
+     *
      * <p>
      * This is the main entry point of the parser.
      *
      * @param prjString a WKT string
-     * @return a list of parameters
+     * @return a {@code PrjElement}
      * @throws PrjParserException if the PRJ cannot be parsed into a CRS for any
      *                            reason
      */
-    public Map<String, String> getParameters(String prjString) {
+    public PrjElement getAsPrjElement(String prjString) {
         CharBuffer s = CharBuffer.wrap(prjString);
         PrjElement e;
         try {
             e = parseNode(s);
         } catch (BufferUnderflowException ex) {
             throw new PrjParserException("Failed to read PRJ.", ex);
         }
-        return PrjMatcher.match(e);
+        return e;
+    }
+
+    /**
+     * Parses a WKT PRJ String into a set of parameters.
+     * <p>
+     * This is the main entry point of the parser.
+     *
+     * @param prjString a WKT string
+     * @return a list of parameters
+     * @throws PrjParserException if the PRJ cannot be parsed into a CRS for any
+     *                            reason
+     */
+    public Map<String, String> getParameters(String prjString) {
+        return PrjMatcher.match(getAsPrjElement(prjString));
     }
 
     /**

src/test/java/org/cts/op/EPSGTransformTest.java

@@ -166,6 +166,20 @@ void testEPSGCodeFrom2100To4326() throws Exception {
         assertTrue(checkEquals2D("EPSG:2100 to EPSG:4326 ", result, pointDest, tolerance));
     }
 
+    @Test
+    void testEPSGCodeFrom27700To4326() throws Exception {
+        String csNameSrc = "EPSG:27700"; //Input EPSG
+        double[] pointSource = new double[]{489581,-55232};
+        String csNameDest = "EPSG:4326";  //Target EPSG
+        double[] pointDest = new double[]{-0.7667563514593325, 49.396886444795};
+        double tolerance = 0.01;
+        CoordinateReferenceSystem inputCRS = cRSFactory.getCRS(csNameSrc);
+        CoordinateReferenceSystem outputCRS = cRSFactory.getCRS(csNameDest);
+        verbose = false;
+        double[] result = transform((GeodeticCRS) inputCRS, (GeodeticCRS) outputCRS, pointSource);
+        assertTrue(checkEquals2D("EPSG:27700 to EPSG:4326 ", result, pointDest, tolerance));
+    }
+
 
     //TODO : Fix me add support to NADGRID
     @Disabled

src/test/java/org/cts/parser/prj/PrjParserTest.java

@@ -28,6 +28,7 @@
 import java.io.RandomAccessFile;
 import java.net.URI;
 import java.nio.CharBuffer;
+import java.util.List;
 import java.util.Map;
 
 import org.cts.CRSFactory;
@@ -319,4 +320,35 @@ void testCompareCRS_PRJ() throws Exception {
         assertNotNull(crs);
         assertFalse(crs.equals(crs2));
     }
+
+    @Test
+    void testWKT2() {
+        String prj = "PROJCRS[\"WGS 84 / UTM zone 31N\",\n" +
+                "BASEGEOGCRS[\"WGS 84\",ENSEMBLE[\"World Geodetic System 1984 ensemble\",MEMBER[\"World Geodetic System 1984 (Transit)\"],MEMBER[\"World Geodetic System 1984 (G730)\"],MEMBER[\"World Geodetic System 1984 (G873)\"],MEMBER[\"World Geodetic System 1984 (G1150)\"],MEMBER[\"World Geodetic System 1984 (G1674)\"],MEMBER[\"World Geodetic System 1984 (G1762)\"],MEMBER[\"World Geodetic System 1984 (G2139)\"],MEMBER[\"World Geodetic System 1984 (G2296)\"],ELLIPSOID[\"WGS 84\",6378137,298.257223563,LENGTHUNIT[\"metre\",1]],ENSEMBLEACCURACY[2.0]],PRIMEM[\"Greenwich\",0,ANGLEUNIT[\"degree\",0.0174532925199433]],ID[\"EPSG\",4326]],\n" +
+                "CONVERSION[\"UTM zone 31N\",METHOD[\"Transverse Mercator\",ID[\"EPSG\",9807]],PARAMETER[\"Latitude of natural origin\",0,ANGLEUNIT[\"degree\",0.0174532925199433],ID[\"EPSG\",8801]],PARAMETER[\"Longitude of natural origin\",3,ANGLEUNIT[\"degree\",0.0174532925199433],ID[\"EPSG\",8802]],PARAMETER[\"Scale factor at natural origin\",0.9996,SCALEUNIT[\"unity\",1],ID[\"EPSG\",8805]],PARAMETER[\"False easting\",500000,LENGTHUNIT[\"metre\",1],ID[\"EPSG\",8806]],PARAMETER[\"False northing\",0,LENGTHUNIT[\"metre\",1],ID[\"EPSG\",8807]]],\n" +
+                "CS[Cartesian,2],\n" +
+                "AXIS[\"(E)\",east,ORDER[1],LENGTHUNIT[\"metre\",1]],\n" +
+                "AXIS[\"(N)\",north,ORDER[2],LENGTHUNIT[\"metre\",1]],\n" +
+                "USAGE[SCOPE[\"Navigation and medium accuracy spatial referencing.\"],AREA[\"Between 0°E and 6°E, northern hemisphere between equator and 84°N, onshore and offshore. Algeria. Andorra. Belgium. Benin. Burkina Faso. Denmark - North Sea. France. Germany - North Sea. Ghana. Luxembourg. Mali. Netherlands. Niger. Nigeria. Norway. Spain. Togo. United Kingdom (UK) - North Sea.\"],BBOX[0,0,84,6]],\n" +
+                "ID[\"EPSG\",32631]]";
+        PrjElement prjElement = parser.getAsPrjElement(prj);
+        assertInstanceOf(PrjNodeElement.class, prjElement);
+        PrjNodeElement firstNode = (PrjNodeElement) prjElement;
+        assertEquals("PROJCRS", firstNode.getName());
+        List<PrjElement> nodes = firstNode.getChildren();
+        PrjNodeElement id_epsg=null;
+        for (PrjElement node : nodes) {
+            if(node instanceof PrjNodeElement) {
+                id_epsg = (PrjNodeElement) node;
+                if (id_epsg.getName().equals("ID")) {
+                    break;
+                }
+            }
+        }
+        assertEquals("ID", id_epsg.getName());
+        List<PrjElement> epsgElement = id_epsg.getChildren();
+        assertEquals(2, epsgElement.size());
+        assertEquals("EPSG", ((PrjStringElement)epsgElement.get(0)).getValue());
+        assertEquals(32631, ((PrjNumberElement)epsgElement.get(1)).getValue());
+    }
 }