DATADOC-294 - Overhaul of collection and type information handling.

Streamlined handling of when and how to write type information into DBObjects being created. Added handling for converting Collections on the top level.

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

@@ -74,11 +74,14 @@ import com.mongodb.DBRef;
  * @author Oliver Gierke
  * @author Jon Brisbin
  */
-public class MappingMongoConverter extends AbstractMongoConverter implements ApplicationContextAware,
-		TypeKeyAware {
+public class MappingMongoConverter extends AbstractMongoConverter implements ApplicationContextAware, TypeKeyAware {
 
 	@SuppressWarnings("rawtypes")
 	private static final TypeInformation<Map> MAP_TYPE_INFORMATION = ClassTypeInformation.from(Map.class);
+	@SuppressWarnings("rawtypes")
+	private static final TypeInformation<Collection> COLLECTION_TYPE_INFORMATION = ClassTypeInformation
+			.from(Collection.class);
+
 	private static final List<Class<?>> VALID_ID_TYPES = Arrays.asList(new Class<?>[] { ObjectId.class, String.class,
 			BigInteger.class, byte[].class });
 
@@ -92,7 +95,6 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 	protected boolean useFieldAccessOnly = true;
 	protected MongoTypeMapper typeMapper;
 
-
 	/**
 	 * Creates a new {@link MappingMongoConverter} given the new {@link MongoDbFactory} and {@link MappingContext}.
 	 * 
@@ -122,7 +124,8 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 	 * @param typeMapper the typeMapper to set
 	 */
 	public void setTypeMapper(MongoTypeMapper typeMapper) {
-		this.typeMapper = typeMapper == null ? new DefaultMongoTypeMapper(DefaultMongoTypeMapper.DEFAULT_TYPE_KEY, mappingContext) : typeMapper;
+		this.typeMapper = typeMapper == null ? new DefaultMongoTypeMapper(DefaultMongoTypeMapper.DEFAULT_TYPE_KEY,
+				mappingContext) : typeMapper;
 	}
 
 	/*
@@ -304,12 +307,13 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 		}
 
 		boolean handledByCustomConverter = conversions.getCustomWriteTarget(obj.getClass(), DBObject.class) != null;
+		TypeInformation<? extends Object> type = ClassTypeInformation.from(obj.getClass());
 		
-		if (!handledByCustomConverter) {
-			typeMapper.writeType(ClassTypeInformation.from(obj.getClass()), dbo);
+		if (!handledByCustomConverter && !(dbo instanceof BasicDBList)) {
+			typeMapper.writeType(type, dbo);
 		}
 
-		writeInternal(obj, dbo);
+		writeInternal(obj, dbo, type);
 	}
 
 	/**
@@ -319,7 +323,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 	 * @param dbo
 	 */
 	@SuppressWarnings("unchecked")
-	protected void writeInternal(final Object obj, final DBObject dbo) {
+	protected void writeInternal(final Object obj, final DBObject dbo, final TypeInformation<?> typeHint) {
 
 		if (null == obj) {
 			return;
@@ -338,8 +342,14 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			return;
 		}
 
+		if (Collection.class.isAssignableFrom(obj.getClass())) {
+			writeCollectionInternal((Collection<?>) obj, COLLECTION_TYPE_INFORMATION, (BasicDBList) dbo);
+			return;
+		}
+
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(obj.getClass());
 		writeInternal(obj, dbo, entity);
+		addCustomTypeKeyIfNecessary(typeHint, obj, dbo);
 	}
 
 	protected void writeInternal(Object obj, final DBObject dbo, MongoPersistentEntity<?> entity) {
@@ -508,7 +518,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 	protected DBObject createCollection(Collection<?> collection, MongoPersistentProperty property) {
 
 		if (!property.isDbReference()) {
-			return createCollectionDBObject(collection, property.getTypeInformation());
+			return writeCollectionInternal(collection, property.getTypeInformation(), new BasicDBList());
 		}
 
 		BasicDBList dbList = new BasicDBList();
@@ -527,15 +537,15 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 	}
 
 	/**
-	 * Creates a new {@link BasicDBList} from the given {@link Collection}.
+	 * Populates the given {@link BasicDBList} with values from the given {@link Collection}.
 	 * 
 	 * @param source the collection to create a {@link BasicDBList} for, must not be {@literal null}.
 	 * @param type the {@link TypeInformation} to consider or {@literal null} if unknown.
+	 * @param sink the {@link BasicDBList} to write to.
 	 * @return
 	 */
-	private BasicDBList createCollectionDBObject(Collection<?> source, TypeInformation<?> type) {
+	private BasicDBList writeCollectionInternal(Collection<?> source, TypeInformation<?> type, BasicDBList sink) {
 
-		BasicDBList dbList = new BasicDBList();
 		TypeInformation<?> componentType = type == null ? null : type.getComponentType();
 
 		for (Object element : source) {
@@ -547,18 +557,17 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			Class<?> elementType = element.getClass();
 
 			if (conversions.isSimpleType(elementType)) {
-				dbList.add(getPotentiallyConvertedSimpleWrite(element));
+				sink.add(getPotentiallyConvertedSimpleWrite(element));
 			} else if (element instanceof Collection || elementType.isArray()) {
-				dbList.add(createCollectionDBObject(asCollection(element), componentType));
+				sink.add(writeCollectionInternal(asCollection(element), componentType, new BasicDBList()));
 			} else {
 				BasicDBObject propDbObj = new BasicDBObject();
-				writeInternal(element, propDbObj);
-				addCustomTypeKeyIfNecessary(componentType, element, propDbObj);
-				dbList.add(propDbObj);
+				writeInternal(element, propDbObj, componentType);
+				sink.add(propDbObj);
 			}
 		}
 
-		return dbList;
+		return sink;
 	}
 
 	/**
@@ -567,8 +576,10 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 	 * @param obj must not be {@literal null}.
 	 * @param dbo must not be {@literal null}.
 	 * @param propertyType must not be {@literal null}.
+	 * @return
 	 */
-	protected void writeMapInternal(Map<Object, Object> obj, DBObject dbo, TypeInformation<?> propertyType) {
+	protected DBObject writeMapInternal(Map<Object, Object> obj, DBObject dbo, TypeInformation<?> propertyType) {
+		
 		for (Map.Entry<Object, Object> entry : obj.entrySet()) {
 			Object key = entry.getKey();
 			Object val = entry.getValue();
@@ -579,17 +590,19 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 				if (val == null || conversions.isSimpleType(val.getClass())) {
 					writeSimpleInternal(val, dbo, simpleKey);
 				} else if (val instanceof Collection) {
-					dbo.put(simpleKey, createCollectionDBObject((Collection<?>) val, propertyType.getMapValueType()));
+					dbo.put(simpleKey,
+							writeCollectionInternal((Collection<?>) val, propertyType.getMapValueType(), new BasicDBList()));
 				} else {
 					DBObject newDbo = new BasicDBObject();
-					writeInternal(val, newDbo);
-					addCustomTypeKeyIfNecessary(propertyType, val, newDbo);
+					writeInternal(val, newDbo, propertyType);
 					dbo.put(simpleKey, newDbo);
 				}
 			} else {
 				throw new MappingException("Cannot use a complex object as a key value.");
 			}
 		}
+		
+		return dbo;
 	}
 
 	/**
@@ -602,11 +615,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 	 */
 	protected void addCustomTypeKeyIfNecessary(TypeInformation<?> type, Object value, DBObject dbObject) {
 
-		if (type == null) {
-			return;
-		}
-		
-		TypeInformation<?> actualType = type.getActualType();
+		TypeInformation<?> actualType = type != null ? type.getActualType() : type;
 		Class<?> reference = actualType == null ? Object.class : actualType.getType();
 
 		boolean notTheSameClass = !value.getClass().equals(reference);

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/DataDoc273Test.java

@@ -18,15 +18,17 @@ package org.springframework.data.mongodb.core.convert;
 import static org.junit.Assert.*;
 import static org.mockito.Mockito.*;
 
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.data.mongodb.MongoDbFactory;
-import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
 
+import com.mongodb.BasicDBList;
 import com.mongodb.BasicDBObject;
 import com.mongodb.DBObject;
 
@@ -51,7 +53,6 @@ public class DataDoc273Test {
 		converter.afterPropertiesSet();
 	}
 
-
 	/**
 	 * @see DATADOC-273
 	 */
@@ -78,6 +79,65 @@ public class DataDoc273Test {
 		assertTrue(mapOfThings2.get("automobile") instanceof Automobile);
 	}
 
+	/**
+	 * @see DATADOC-294
+	 */
+	@Test
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	public void convertListOfThings() {
+		Plane plane = new Plane("Boeing", 4);
+		Train train = new Train("Santa Fe", 200);
+		Automobile automobile = new Automobile("Tesla", "Roadster", 2);
+
+		List listOfThings = new ArrayList();
+		listOfThings.add(plane);
+		listOfThings.add(train);
+		listOfThings.add(automobile);
+
+		DBObject result = new BasicDBList();
+		converter.write(listOfThings, result);
+		System.out.println(result.toString());
+
+		List listOfThings2 = converter.read(List.class, result);
+
+		assertTrue(listOfThings2.get(0) instanceof Plane);
+		assertTrue(listOfThings2.get(1) instanceof Train);
+		assertTrue(listOfThings2.get(2) instanceof Automobile);
+	}
+
+	/**
+	 * @see DATADOC-294
+	 */
+	@Test
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	public void convertListOfThings_NestedInMap() {
+
+		Plane plane = new Plane("Boeing", 4);
+		Train train = new Train("Santa Fe", 200);
+		Automobile automobile = new Automobile("Tesla", "Roadster", 2);
+
+		List listOfThings = new ArrayList();
+		listOfThings.add(plane);
+		listOfThings.add(train);
+		listOfThings.add(automobile);
+
+		Map box = new HashMap();
+		box.put("one", listOfThings);
+
+		Shipment shipment = new Shipment(box);
+
+		DBObject result = new BasicDBObject();
+		converter.write(shipment, result);
+
+		Shipment shipment2 = converter.read(Shipment.class, result);
+
+		List listOfThings2 = (List) shipment2.getBoxes().get("one");
+
+		assertTrue(listOfThings2.get(0) instanceof Plane);
+		assertTrue(listOfThings2.get(1) instanceof Train);
+		assertTrue(listOfThings2.get(2) instanceof Automobile);
+	}
+
 	class Plane {
 
 		String maker;
@@ -112,4 +172,18 @@ public class DataDoc273Test {
 			this.numberOfDoors = numberOfDoors;
 		}
 	}
+
+	@SuppressWarnings("rawtypes")
+	public class Shipment {
+		
+		Map boxes = new HashMap();
+
+		public Shipment(Map boxes) {
+			this.boxes = boxes;
+		}
+
+		public Map getBoxes() {
+			return boxes;
+		}
+	}
 }