DATACMNS-437 - Polishing of newly introduced geo value objects.

Polished JavaDoc. Simplified equals(…) and hashCode() methods where possible. Added additional null checks where appropriate. Removed obsolete generics in Polygon and switched to an immutable collection for the Points making up the Polygon. Added missing toString() method to Polygon.
Added test cases for String representations.

Related pull request: #68.

src/test/java/org/springframework/data/geo/BoxUnitTests.java

@@ -52,4 +52,13 @@ public class BoxUnitTests {
 		assertThat(first.hashCode(), is(second.hashCode()));
 		assertThat(first.hashCode(), is(not(third.hashCode())));
 	}
+
+	/**
+	 * @see DATACMNS-437
+	 */
+	@Test
+	public void testToString() {
+
+		assertThat(first.toString(), is("Box [Point [x=1.000000, y=1.000000], Point [x=2.000000, y=2.000000]]"));
+	}
 }

src/test/java/org/springframework/data/geo/CircleUnitTests.java

@@ -61,4 +61,13 @@ public class CircleUnitTests {
 		assertThat(left, is(right));
 		assertThat(right, is(left));
 	}
+
+	/**
+	 * @see DATACMNS-437
+	 */
+	@Test
+	public void testToString() {
+
+		assertThat(new Circle(1, 1, 1).toString(), is("Circle: [center=Point [x=1.000000, y=1.000000], radius=1.0]"));
+	}
 }

src/test/java/org/springframework/data/geo/PointUnitTests.java

@@ -52,6 +52,7 @@ public class PointUnitTests {
 	 */
 	@Test
 	public void invokingToStringWorksCorrectly() {
-		new Point(1.5, 1.5).toString();
+		assertThat(new Point(1.5, 1.5).toString(), is("Point [x=1.500000, y=1.500000]"));
 	}
+
 }

src/test/java/org/springframework/data/geo/PolygonUnitTests.java

@@ -63,4 +63,14 @@ public class PolygonUnitTests {
 		assertThat(left, is(right));
 		assertThat(right, is(left));
 	}
+
+	/**
+	 * @see DATACMNS-437
+	 */
+	@Test
+	public void testToString() {
+
+		assertThat(new Polygon(third, second, first).toString(),
+				is("Polygon: [Point [x=3.000000, y=3.000000],Point [x=2.000000, y=2.000000],Point [x=1.000000, y=1.000000]]"));
+	}
 }