DATAMONGO-2168 - Polishing.

MetadataBackedField no longer fails when Path detects reference to field within java.lang.Class. This can happen when splitting the property name via camel case where the first part matches to class which resolves to the getClass() call on java.lang.Object. When then the 2nd part also maps to a method (like getName()) on Class an error would be thrown.

Original Pull Request: #631

Author: christophstrobl

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/QueryMapper.java

@@ -1028,6 +1028,11 @@ private PersistentPropertyPath<MongoPersistentProperty> getPath(String pathExpre
 			try {
 
 				PropertyPath path = PropertyPath.from(pathExpression.replaceAll("\\.\\d+", ""), entity.getTypeInformation());
+
+				if (isPathToJavaLangClassProperty(path)) {
+					return null;
+				}
+
 				PersistentPropertyPath<MongoPersistentProperty> propertyPath = mappingContext.getPersistentPropertyPath(path);
 
 				Iterator<MongoPersistentProperty> iterator = propertyPath.iterator();
@@ -1053,6 +1058,14 @@ private PersistentPropertyPath<MongoPersistentProperty> getPath(String pathExpre
 			}
 		}
 
+		private boolean isPathToJavaLangClassProperty(PropertyPath path) {
+
+			if (path.getType().equals(Class.class) && path.getLeafProperty().getOwningType().getType().equals(Class.class)) {
+				return true;
+			}
+			return false;
+		}
+
 		/**
 		 * Return the {@link Converter} to be used to created the mapped key. Default implementation will use
 		 * {@link PropertyToFieldNameConverter}.

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/QueryMapperUnitTests.java

@@ -810,6 +810,15 @@ public void getMappedObjectShouldNotMapTypeHint() {
 		assertThat(mappedObject).containsEntry("className", "foo");
 	}
 
+	@Test // DATAMONGO-2168
+	public void getMappedObjectShouldIgnorePathsLeadingToJavaLangClassProperties/* like Class#getName() */() {
+
+		org.bson.Document update = new org.bson.Document("className", "foo");
+		org.bson.Document mappedObject = mapper.getMappedObject(update, context.getPersistentEntity(UserEntity.class));
+
+		assertThat(mappedObject).containsEntry("className", "foo");
+	}
+
 	@Document
 	public class Foo {
 		@Id private ObjectId id;
@@ -855,7 +864,7 @@ enum Enum {
 
 	class UserEntity {
 		String id;
-		List<String> publishers = new ArrayList<String>();
+		List<String> publishers = new ArrayList<>();
 	}
 
 	class CustomizedField {