Add Projection.getEpsg() method to get epsg/srid code as integer

Author: jericks

src/main/groovy/geoscript/proj/Projection.groovy

@@ -70,6 +70,14 @@ class Projection {
         return CRS.lookupIdentifier(crs, true)
     }
 
+    /**
+     * Get the EPSG code
+     * @return The EPSG code
+     */
+    int getEpsg() {
+        CRS.lookupEpsgCode(crs, true)
+    }
+
     /**
      * Get the well known text
      * @return The well known texts

src/test/groovy/geoscript/proj/ProjectionTestCase.groovy

@@ -32,6 +32,15 @@ class ProjectionTestCase {
         assertEquals "EPSG:2927", p1.id
     }
 
+    @Test void getEpsg() {
+        Projection p = new Projection("EPSG:2927")
+        assertEquals 2927, p.epsg
+        p = new Projection("EPSG:4326")
+        assertEquals 4326, p.epsg
+        p = new Projection("EPSG:3857")
+        assertEquals 3857, p.epsg
+    }
+
     @Test void getWkt() {
         Projection p1 = new Projection("EPSG:4326")