DATACMNS-1112 - Cache instances of ReturnedType to avoid repeated reflection inspection.

We now keep instances of ReturnedType around to avoid the repeated reflection inspection for constructor and parameter name detection for class types and projection information for interfaces.

src/test/java/org/springframework/data/repository/query/ReturnedTypeUnitTests.java

@@ -157,6 +157,17 @@ public class ReturnedTypeUnitTests {
 		assertThat(properties).containsExactly("firstname");
 	}
 
+	@Test // DATACMNS-1112
+	public void cachesInstancesBySourceTypes() {
+
+		SpelAwareProxyProjectionFactory factory = new SpelAwareProxyProjectionFactory();
+
+		ReturnedType left = ReturnedType.of(Child.class, Object.class, factory);
+		ReturnedType right = ReturnedType.of(Child.class, Object.class, factory);
+
+		assertThat(left).isSameAs(right);
+	}
+
 	private static ReturnedType getReturnedType(String methodName, Class<?>... parameters) throws Exception {
 		return getQueryMethod(methodName, parameters).getResultProcessor().getReturnedType();
 	}