DATAMONGO-1245 - Add support for Query By Example.

An explorative approach to QBE trying find possibilities and limitations. We now support querying documents by providing a sample of the given object holding compare values. For the sake of partial matching we flatten out nested structures so we can create different queries for matching like:

{ _id : 1, nested : { value : "conflux" } }
{ _id : 1, nested.value : { "conflux" } }

This is useful when you want so search using a only partially filled nested document. String matching can be configured to wrap strings with $regex which creates { firstname : { $regex : "^foo", $options: "i" } } when using StringMatchMode.STARTING along with the ignoreCaseOption. DBRefs and geo structures such as Point or GeoJsonPoint is converted to their according structure.

Related tickets: DATACMNS-810.
Original pull request: #341.

Author: christophstrobl

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

@@ -51,6 +51,7 @@
 import org.springframework.data.annotation.Id;
 import org.springframework.data.authentication.UserCredentials;
 import org.springframework.data.convert.EntityReader;
+import org.springframework.data.domain.Example;
 import org.springframework.data.geo.Distance;
 import org.springframework.data.geo.GeoResult;
 import org.springframework.data.geo.GeoResults;
@@ -340,8 +341,8 @@ public CloseableIterator<T> doInCollection(DBCollection collection) throws Mongo
 				DBCursor cursor = collection.find(mappedQuery, mappedFields);
 				QueryCursorPreparer cursorPreparer = new QueryCursorPreparer(query, entityType);
 
-				ReadDbObjectCallback<T> readCallback = new ReadDbObjectCallback<T>(mongoConverter, entityType,
-						collection.getName());
+				ReadDbObjectCallback<T> readCallback = new ReadDbObjectCallback<T>(mongoConverter, entityType, collection
+						.getName());
 
 				return new CloseableIterableCursorAdapter<T>(cursorPreparer.prepare(cursor), exceptionTranslator, readCallback);
 			}
@@ -374,8 +375,8 @@ public CommandResult doInDB(DB db) throws MongoException, DataAccessException {
 	 */
 	@Deprecated
 	public CommandResult executeCommand(final DBObject command, final int options) {
-		return executeCommand(command,
-				(options & Bytes.QUERYOPTION_SLAVEOK) != 0 ? ReadPreference.secondaryPreferred() : ReadPreference.primary());
+		return executeCommand(command, (options & Bytes.QUERYOPTION_SLAVEOK) != 0 ? ReadPreference.secondaryPreferred()
+				: ReadPreference.primary());
 	}
 
 	/*
@@ -421,8 +422,7 @@ public void executeQuery(Query query, String collectionName, DocumentCallbackHan
 	 * @param preparer allows for customization of the {@link DBCursor} used when iterating over the result set, (apply
 	 *          limits, skips and so on).
 	 */
-	protected void executeQuery(Query query, String collectionName, DocumentCallbackHandler dch,
-			CursorPreparer preparer) {
+	protected void executeQuery(Query query, String collectionName, DocumentCallbackHandler dch, CursorPreparer preparer) {
 
 		Assert.notNull(query);
 
@@ -637,6 +637,17 @@ public <T> T findById(Object id, Class<T> entityClass, String collectionName) {
 		return doFindOne(collectionName, new BasicDBObject(idKey, id), null, entityClass);
 	}
 
+	public <S extends T, T> List<T> findByExample(S sample) {
+		return findByExample(new Example<S>(sample));
+	}
+
+	@SuppressWarnings("unchecked")
+	public <S extends T, T> List<T> findByExample(Example<S> sample) {
+
+		Assert.notNull(sample, "Sample object must not be null!");
+		return (List<T>) find(new Query(new Criteria().alike(sample)), sample.getSampleType());
+	}
+
 	public <T> GeoResults<T> geoNear(NearQuery near, Class<T> entityClass) {
 		return geoNear(near, entityClass, determineCollectionName(entityClass));
 	}
@@ -672,8 +683,8 @@ public <T> GeoResults<T> geoNear(NearQuery near, Class<T> entityClass, String co
 		List<Object> results = (List<Object>) commandResult.get("results");
 		results = results == null ? Collections.emptyList() : results;
 
-		DbObjectCallback<GeoResult<T>> callback = new GeoNearResultDbObjectCallback<T>(
-				new ReadDbObjectCallback<T>(mongoConverter, entityClass, collectionName), near.getMetric());
+		DbObjectCallback<GeoResult<T>> callback = new GeoNearResultDbObjectCallback<T>(new ReadDbObjectCallback<T>(
+				mongoConverter, entityClass, collectionName), near.getMetric());
 		List<GeoResult<T>> result = new ArrayList<GeoResult<T>>(results.size());
 
 		int index = 0;
@@ -749,9 +760,8 @@ public long count(final Query query, String collectionName) {
 	public long count(Query query, Class<?> entityClass, String collectionName) {
 
 		Assert.hasText(collectionName);
-		final DBObject dbObject = query == null ? null
-				: queryMapper.getMappedObject(query.getQueryObject(),
-						entityClass == null ? null : mappingContext.getPersistentEntity(entityClass));
+		final DBObject dbObject = query == null ? null : queryMapper.getMappedObject(query.getQueryObject(),
+				entityClass == null ? null : mappingContext.getPersistentEntity(entityClass));
 
 		return execute(collectionName, new CollectionCallback<Long>() {
 			public Long doInCollection(DBCollection collection) throws MongoException, DataAccessException {
@@ -1030,8 +1040,8 @@ public Object doInCollection(DBCollection collection) throws MongoException, Dat
 				MongoAction mongoAction = new MongoAction(writeConcern, MongoActionOperation.INSERT, collectionName,
 						entityClass, dbDoc, null);
 				WriteConcern writeConcernToUse = prepareWriteConcern(mongoAction);
-				WriteResult writeResult = writeConcernToUse == null ? collection.insert(dbDoc)
-						: collection.insert(dbDoc, writeConcernToUse);
+				WriteResult writeResult = writeConcernToUse == null ? collection.insert(dbDoc) : collection.insert(dbDoc,
+						writeConcernToUse);
 				handleAnyWriteResultErrors(writeResult, dbDoc, MongoActionOperation.INSERT);
 				return dbDoc.get(ID_FIELD);
 			}
@@ -1052,8 +1062,8 @@ public Void doInCollection(DBCollection collection) throws MongoException, DataA
 				MongoAction mongoAction = new MongoAction(writeConcern, MongoActionOperation.INSERT_LIST, collectionName, null,
 						null, null);
 				WriteConcern writeConcernToUse = prepareWriteConcern(mongoAction);
-				WriteResult writeResult = writeConcernToUse == null ? collection.insert(dbDocList)
-						: collection.insert(dbDocList.toArray((DBObject[]) new BasicDBObject[dbDocList.size()]), writeConcernToUse);
+				WriteResult writeResult = writeConcernToUse == null ? collection.insert(dbDocList) : collection.insert(
+						dbDocList.toArray((DBObject[]) new BasicDBObject[dbDocList.size()]), writeConcernToUse);
 				handleAnyWriteResultErrors(writeResult, null, MongoActionOperation.INSERT_LIST);
 				return null;
 			}
@@ -1083,8 +1093,8 @@ public Object doInCollection(DBCollection collection) throws MongoException, Dat
 				MongoAction mongoAction = new MongoAction(writeConcern, MongoActionOperation.SAVE, collectionName, entityClass,
 						dbDoc, null);
 				WriteConcern writeConcernToUse = prepareWriteConcern(mongoAction);
-				WriteResult writeResult = writeConcernToUse == null ? collection.save(dbDoc)
-						: collection.save(dbDoc, writeConcernToUse);
+				WriteResult writeResult = writeConcernToUse == null ? collection.save(dbDoc) : collection.save(dbDoc,
+						writeConcernToUse);
 				handleAnyWriteResultErrors(writeResult, dbDoc, MongoActionOperation.SAVE);
 				return dbDoc.get(ID_FIELD);
 			}
@@ -1137,10 +1147,10 @@ public WriteResult doInCollection(DBCollection collection) throws MongoException
 
 				increaseVersionForUpdateIfNecessary(entity, update);
 
-				DBObject queryObj = query == null ? new BasicDBObject()
-						: queryMapper.getMappedObject(query.getQueryObject(), entity);
-				DBObject updateObj = update == null ? new BasicDBObject()
-						: updateMapper.getMappedObject(update.getUpdateObject(), entity);
+				DBObject queryObj = query == null ? new BasicDBObject() : queryMapper.getMappedObject(query.getQueryObject(),
+						entity);
+				DBObject updateObj = update == null ? new BasicDBObject() : updateMapper.getMappedObject(
+						update.getUpdateObject(), entity);
 
 				if (LOGGER.isDebugEnabled()) {
 					LOGGER.debug("Calling update using query: {} and update: {} in collection: {}",
@@ -1281,9 +1291,9 @@ private void assertUpdateableIdIfNotSet(Object entity) {
 		Object idValue = persistentEntity.getPropertyAccessor(entity).getProperty(idProperty);
 
 		if (idValue == null && !MongoSimpleTypes.AUTOGENERATED_ID_TYPES.contains(idProperty.getType())) {
-			throw new InvalidDataAccessApiUsageException(
-					String.format("Cannot autogenerate id of type %s for entity of type %s!", idProperty.getType().getName(),
-							entity.getClass().getName()));
+			throw new InvalidDataAccessApiUsageException(String.format(
+					"Cannot autogenerate id of type %s for entity of type %s!", idProperty.getType().getName(), entity.getClass()
+							.getName()));
 		}
 	}
 
@@ -1322,12 +1332,12 @@ public WriteResult doInCollection(DBCollection collection) throws MongoException
 				WriteConcern writeConcernToUse = prepareWriteConcern(mongoAction);
 
 				if (LOGGER.isDebugEnabled()) {
-					LOGGER.debug("Remove using query: {} in collection: {}.",
-							new Object[] { serializeToJsonSafely(dboq), collection.getName() });
+					LOGGER.debug("Remove using query: {} in collection: {}.", new Object[] { serializeToJsonSafely(dboq),
+							collection.getName() });
 				}
 
-				WriteResult wr = writeConcernToUse == null ? collection.remove(dboq)
-						: collection.remove(dboq, writeConcernToUse);
+				WriteResult wr = writeConcernToUse == null ? collection.remove(dboq) : collection.remove(dboq,
+						writeConcernToUse);
 
 				handleAnyWriteResultErrors(wr, dboq, MongoActionOperation.REMOVE);
 
@@ -1343,8 +1353,8 @@ public <T> List<T> findAll(Class<T> entityClass) {
 	}
 
 	public <T> List<T> findAll(Class<T> entityClass, String collectionName) {
-		return executeFindMultiInternal(new FindCallback(null), null,
-				new ReadDbObjectCallback<T>(mongoConverter, entityClass, collectionName), collectionName);
+		return executeFindMultiInternal(new FindCallback(null), null, new ReadDbObjectCallback<T>(mongoConverter,
+				entityClass, collectionName), collectionName);
 	}
 
 	public <T> MapReduceResults<T> mapReduce(String inputCollectionName, String mapFunction, String reduceFunction,
@@ -1360,8 +1370,8 @@ public <T> MapReduceResults<T> mapReduce(String inputCollectionName, String mapF
 
 	public <T> MapReduceResults<T> mapReduce(Query query, String inputCollectionName, String mapFunction,
 			String reduceFunction, Class<T> entityClass) {
-		return mapReduce(query, inputCollectionName, mapFunction, reduceFunction, new MapReduceOptions().outputTypeInline(),
-				entityClass);
+		return mapReduce(query, inputCollectionName, mapFunction, reduceFunction,
+				new MapReduceOptions().outputTypeInline(), entityClass);
 	}
 
 	public <T> MapReduceResults<T> mapReduce(Query query, String inputCollectionName, String mapFunction,
@@ -1372,9 +1382,8 @@ public <T> MapReduceResults<T> mapReduce(Query query, String inputCollectionName
 		DBCollection inputCollection = getCollection(inputCollectionName);
 
 		MapReduceCommand command = new MapReduceCommand(inputCollection, mapFunc, reduceFunc,
-				mapReduceOptions.getOutputCollection(), mapReduceOptions.getOutputType(),
-				query == null || query.getQueryObject() == null ? null
-						: queryMapper.getMappedObject(query.getQueryObject(), null));
+				mapReduceOptions.getOutputCollection(), mapReduceOptions.getOutputType(), query == null
+						|| query.getQueryObject() == null ? null : queryMapper.getMappedObject(query.getQueryObject(), null));
 
 		copyMapReduceOptionsToCommand(query, mapReduceOptions, command);
 
@@ -1710,8 +1719,8 @@ protected <T> T doFindOne(String collectionName, DBObject query, DBObject fields
 					mappedFields, entityClass, collectionName);
 		}
 
-		return executeFindOneInternal(new FindOneCallback(mappedQuery, mappedFields),
-				new ReadDbObjectCallback<T>(this.mongoConverter, entityClass, collectionName), collectionName);
+		return executeFindOneInternal(new FindOneCallback(mappedQuery, mappedFields), new ReadDbObjectCallback<T>(
+				this.mongoConverter, entityClass, collectionName), collectionName);
 	}
 
 	/**
@@ -1725,8 +1734,8 @@ protected <T> T doFindOne(String collectionName, DBObject query, DBObject fields
 	 * @return the List of converted objects.
 	 */
 	protected <T> List<T> doFind(String collectionName, DBObject query, DBObject fields, Class<T> entityClass) {
-		return doFind(collectionName, query, fields, entityClass, null,
-				new ReadDbObjectCallback<T>(this.mongoConverter, entityClass, collectionName));
+		return doFind(collectionName, query, fields, entityClass, null, new ReadDbObjectCallback<T>(this.mongoConverter,
+				entityClass, collectionName));
 	}
 
 	/**
@@ -1744,8 +1753,8 @@ protected <T> List<T> doFind(String collectionName, DBObject query, DBObject fie
 	 */
 	protected <T> List<T> doFind(String collectionName, DBObject query, DBObject fields, Class<T> entityClass,
 			CursorPreparer preparer) {
-		return doFind(collectionName, query, fields, entityClass, preparer,
-				new ReadDbObjectCallback<T>(mongoConverter, entityClass, collectionName));
+		return doFind(collectionName, query, fields, entityClass, preparer, new ReadDbObjectCallback<T>(mongoConverter,
+				entityClass, collectionName));
 	}
 
 	protected <S, T> List<T> doFind(String collectionName, DBObject query, DBObject fields, Class<S> entityClass,
@@ -1898,8 +1907,8 @@ private <T> T executeFindOneInternal(CollectionCallback<DBObject> collectionCall
 			DbObjectCallback<T> objectCallback, String collectionName) {
 
 		try {
-			T result = objectCallback
-					.doWith(collectionCallback.doInCollection(getAndPrepareCollection(getDb(), collectionName)));
+			T result = objectCallback.doWith(collectionCallback.doInCollection(getAndPrepareCollection(getDb(),
+					collectionName)));
 			return result;
 		} catch (RuntimeException e) {
 			throw potentiallyConvertRuntimeException(e, exceptionTranslator);
@@ -1924,8 +1933,8 @@ private <T> T executeFindOneInternal(CollectionCallback<DBObject> collectionCall
 	 * @param collectionName the collection to be queried
 	 * @return
 	 */
-	private <T> List<T> executeFindMultiInternal(CollectionCallback<DBCursor> collectionCallback, CursorPreparer preparer,
-			DbObjectCallback<T> objectCallback, String collectionName) {
+	private <T> List<T> executeFindMultiInternal(CollectionCallback<DBCursor> collectionCallback,
+			CursorPreparer preparer, DbObjectCallback<T> objectCallback, String collectionName) {
 
 		try {
 
@@ -2015,8 +2024,8 @@ String determineCollectionName(Class<?> entityClass) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
 		if (entity == null) {
-			throw new InvalidDataAccessApiUsageException(
-					"No Persistent Entity information found for the class " + entityClass.getName());
+			throw new InvalidDataAccessApiUsageException("No Persistent Entity information found for the class "
+					+ entityClass.getName());
 		}
 		return entity.getCollection();
 	}
@@ -2080,8 +2089,8 @@ private void handleCommandError(CommandResult result, DBObject source) {
 			String error = result.getErrorMessage();
 			error = error == null ? "NO MESSAGE" : error;
 
-			throw new InvalidDataAccessApiUsageException(
-					"Command execution failed:  Error [" + error + "], Command = " + source, ex);
+			throw new InvalidDataAccessApiUsageException("Command execution failed:  Error [" + error + "], Command = "
+					+ source, ex);
 		}
 	}
 
@@ -2277,8 +2286,7 @@ public T doWith(DBObject object) {
 
 	class UnwrapAndReadDbObjectCallback<T> extends ReadDbObjectCallback<T> {
 
-		public UnwrapAndReadDbObjectCallback(EntityReader<? super T, DBObject> reader, Class<T> type,
-				String collectionName) {
+		public UnwrapAndReadDbObjectCallback(EntityReader<? super T, DBObject> reader, Class<T> type, String collectionName) {
 			super(reader, type, collectionName);
 		}
 

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

@@ -117,6 +117,10 @@ public Point convert(DBObject source) {
 
 			Assert.isTrue(source.keySet().size() == 2, "Source must contain 2 elements");
 
+			if (source.containsField("type")) {
+				return DbObjectToGeoJsonPointConverter.INSTANCE.convert(source);
+			}
+
 			return new Point((Double) source.get("x"), (Double) source.get("y"));
 		}
 	}

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

@@ -0,0 +1,229 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.convert;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Stack;
+import java.util.regex.Pattern;
+
+import org.springframework.data.domain.Example;
+import org.springframework.data.domain.Example.NullHandler;
+import org.springframework.data.domain.Example.StringMatcher;
+import org.springframework.data.domain.PropertySpecifier;
+import org.springframework.data.mapping.PropertyHandler;
+import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+import org.springframework.data.mongodb.core.query.MongoRegexCreator;
+import org.springframework.data.mongodb.core.query.SerializationUtils;
+import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
+
+import com.mongodb.BasicDBObject;
+import com.mongodb.DBObject;
+
+/**
+ * @author Christoph Strobl
+ * @since 1.8
+ */
+public class MongoExampleMapper {
+
+	private final MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+	private final MongoConverter converter;
+
+	public MongoExampleMapper(MongoConverter converter) {
+
+		this.converter = converter;
+		this.mappingContext = converter.getMappingContext();
+	}
+
+	/**
+	 * Returns the given {@link Example} as {@link DBObject} holding matching values extracted from
+	 * {@link Example#getProbe()}.
+	 * 
+	 * @param example
+	 * @return
+	 * @since 1.8
+	 */
+	public DBObject getMappedExample(Example<?> example) {
+		return getMappedExample(example, mappingContext.getPersistentEntity(example.getSampleType()));
+	}
+
+	/**
+	 * Returns the given {@link Example} as {@link DBObject} holding matching values extracted from
+	 * {@link Example#getProbe()}.
+	 * 
+	 * @param example
+	 * @param entity
+	 * @return
+	 * @since 1.8
+	 */
+	public DBObject getMappedExample(Example<?> example, MongoPersistentEntity<?> entity) {
+
+		DBObject reference = (DBObject) converter.convertToMongoType(example.getSampleObject());
+
+		if (entity.hasIdProperty() && entity.getIdentifierAccessor(example.getSampleObject()).getIdentifier() == null) {
+			reference.removeField(entity.getIdProperty().getFieldName());
+		}
+
+		applyPropertySpecs("", reference, example);
+
+		return ObjectUtils.nullSafeEquals(NullHandler.INCLUDE, example.getNullHandler()) ? reference : new BasicDBObject(
+				SerializationUtils.flatMap(reference));
+	}
+
+	private String getMappedPropertyPath(String path, Example<?> example) {
+
+		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(example.getSampleType());
+
+		Iterator<String> parts = Arrays.asList(path.split("\\.")).iterator();
+
+		final Stack<MongoPersistentProperty> stack = new Stack<MongoPersistentProperty>();
+
+		List<String> resultParts = new ArrayList<String>();
+
+		while (parts.hasNext()) {
+
+			final String part = parts.next();
+			MongoPersistentProperty prop = entity.getPersistentProperty(part);
+
+			if (prop == null) {
+
+				entity.doWithProperties(new PropertyHandler<MongoPersistentProperty>() {
+
+					@Override
+					public void doWithPersistentProperty(MongoPersistentProperty property) {
+
+						if (property.getFieldName().equals(part)) {
+							stack.push(property);
+						}
+					}
+				});
+
+				if (stack.isEmpty()) {
+					return "";
+				}
+				prop = stack.pop();
+			}
+
+			resultParts.add(prop.getName());
+
+			if (prop.isEntity() && mappingContext.hasPersistentEntityFor(prop.getActualType())) {
+				entity = mappingContext.getPersistentEntity(prop.getActualType());
+			} else {
+				break;
+			}
+		}
+
+		return StringUtils.collectionToDelimitedString(resultParts, ".");
+
+	}
+
+	private void applyPropertySpecs(String path, DBObject source, Example<?> example) {
+
+		if (!(source instanceof BasicDBObject)) {
+			return;
+		}
+
+		Iterator<Map.Entry<String, Object>> iter = ((BasicDBObject) source).entrySet().iterator();
+
+		while (iter.hasNext()) {
+
+			Map.Entry<String, Object> entry = iter.next();
+
+			if (entry.getKey().equals("_id") && entry.getValue() == null) {
+				iter.remove();
+				continue;
+			}
+
+			String propertyPath = StringUtils.hasText(path) ? path + "." + entry.getKey() : entry.getKey();
+
+			String mappedPropertyPath = getMappedPropertyPath(propertyPath, example);
+			if (example.isIgnoredPath(propertyPath) || example.isIgnoredPath(mappedPropertyPath)) {
+				iter.remove();
+				continue;
+			}
+
+			PropertySpecifier specifier = null;
+			StringMatcher stringMatcher = example.getDefaultStringMatcher();
+			Object value = entry.getValue();
+			boolean ignoreCase = example.isIngnoreCaseEnabled();
+
+			if (example.hasPropertySpecifiers()) {
+
+				mappedPropertyPath = example.hasPropertySpecifier(propertyPath) ? propertyPath : getMappedPropertyPath(
+						propertyPath, example);
+
+				specifier = example.getPropertySpecifier(mappedPropertyPath);
+
+				if (specifier != null) {
+					if (specifier.hasStringMatcher()) {
+						stringMatcher = specifier.getStringMatcher();
+					}
+					if (specifier.getIgnoreCase() != null) {
+						ignoreCase = specifier.getIgnoreCase();
+					}
+
+				}
+			}
+
+			// TODO: should a PropertySpecifier outrule the later on string matching?
+			if (specifier != null) {
+
+				value = specifier.transformValue(value);
+				if (value == null) {
+					iter.remove();
+					continue;
+				}
+
+				entry.setValue(value);
+			}
+
+			if (entry.getValue() instanceof String) {
+				applyStringMatcher(entry, stringMatcher, ignoreCase);
+			} else if (entry.getValue() instanceof BasicDBObject) {
+				applyPropertySpecs(propertyPath, (BasicDBObject) entry.getValue(), example);
+			}
+		}
+	}
+
+	private void applyStringMatcher(Map.Entry<String, Object> entry, StringMatcher stringMatcher, boolean ignoreCase) {
+
+		BasicDBObject dbo = new BasicDBObject();
+
+		if (ObjectUtils.nullSafeEquals(StringMatcher.DEFAULT, stringMatcher)) {
+
+			if (ignoreCase) {
+				dbo.put("$regex", Pattern.quote((String) entry.getValue()));
+				entry.setValue(dbo);
+			}
+		} else {
+
+			String expression = MongoRegexCreator.INSTANCE.toRegularExpression((String) entry.getValue(),
+					stringMatcher.getPartType());
+			dbo.put("$regex", expression);
+			entry.setValue(dbo);
+		}
+
+		if (ignoreCase) {
+			dbo.put("$options", "i");
+		}
+	}
+}

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

@@ -27,6 +27,7 @@
 import org.springframework.core.convert.ConversionException;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.converter.Converter;
+import org.springframework.data.domain.Example;
 import org.springframework.data.mapping.Association;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PropertyPath;
@@ -70,6 +71,7 @@ private enum MetaMapping {
 	private final ConversionService conversionService;
 	private final MongoConverter converter;
 	private final MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+	private final MongoExampleMapper exampleMapper;
 
 	/**
 	 * Creates a new {@link QueryMapper} with the given {@link MongoConverter}.
@@ -83,6 +85,7 @@ public QueryMapper(MongoConverter converter) {
 		this.conversionService = converter.getConversionService();
 		this.converter = converter;
 		this.mappingContext = converter.getMappingContext();
+		this.exampleMapper = new MongoExampleMapper(converter);
 	}
 
 	/**
@@ -239,6 +242,10 @@ protected DBObject getMappedKeyword(Keyword keyword, MongoPersistentEntity<?> en
 			return new BasicDBObject(keyword.getKey(), newConditions);
 		}
 
+		if (keyword.isSample()) {
+			return exampleMapper.getMappedExample(keyword.<Example<?>> getValue(), entity);
+		}
+
 		return new BasicDBObject(keyword.getKey(), convertSimpleOrDBObject(keyword.getValue(), entity));
 	}
 
@@ -254,8 +261,8 @@ protected DBObject getMappedKeyword(Field property, Keyword keyword) {
 		boolean needsAssociationConversion = property.isAssociation() && !keyword.isExists();
 		Object value = keyword.getValue();
 
-		Object convertedValue = needsAssociationConversion ? convertAssociation(value, property)
-				: getMappedValue(property.with(keyword.getKey()), value);
+		Object convertedValue = needsAssociationConversion ? convertAssociation(value, property) : getMappedValue(
+				property.with(keyword.getKey()), value);
 
 		return new BasicDBObject(keyword.key, convertedValue);
 	}
@@ -477,8 +484,8 @@ public Object convertId(Object id) {
 		}
 
 		try {
-			return conversionService.canConvert(id.getClass(), ObjectId.class) ? conversionService.convert(id, ObjectId.class)
-					: delegateConvertToMongoType(id, null);
+			return conversionService.canConvert(id.getClass(), ObjectId.class) ? conversionService
+					.convert(id, ObjectId.class) : delegateConvertToMongoType(id, null);
 		} catch (ConversionException o_O) {
 			return delegateConvertToMongoType(id, null);
 		}
@@ -566,6 +573,16 @@ public boolean isGeometry() {
 			return "$geometry".equalsIgnoreCase(key);
 		}
 
+		/**
+		 * Returns wheter the current keyword indicates a sample object.
+		 * 
+		 * @return
+		 * @since 1.8
+		 */
+		public boolean isSample() {
+			return "$sample".equalsIgnoreCase(key);
+		}
+
 		public boolean hasIterableValue() {
 			return value instanceof Iterable;
 		}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/Criteria.java

@@ -26,6 +26,7 @@
 import java.util.regex.Pattern;
 
 import org.bson.BSON;
+import org.springframework.data.domain.Example;
 import org.springframework.data.geo.Circle;
 import org.springframework.data.geo.Point;
 import org.springframework.data.geo.Shape;
@@ -88,6 +89,30 @@ public static Criteria where(String key) {
 		return new Criteria(key);
 	}
 
+	/**
+	 * Static factory method to create a {@link Criteria} matching an example object.
+	 * 
+	 * @param example must not be {@literal null}.
+	 * @return
+	 * @see Criteria#alike(Example)
+	 * @since 1.8
+	 */
+	public static Criteria byExample(Object example) {
+		return byExample(new Example<Object>(example));
+	}
+
+	/**
+	 * Static factory method to create a {@link Criteria} matching an example object.
+	 * 
+	 * @param example must not be {@literal null}.
+	 * @return
+	 * @see Criteria#alike(Example)
+	 * @since 1.8
+	 */
+	public static Criteria byExample(Example<?> example) {
+		return new Criteria().alike(example);
+	}
+
 	/**
 	 * Static factory method to create a Criteria using the provided key
 	 * 
@@ -191,8 +216,8 @@ public Criteria gte(Object o) {
 	 */
 	public Criteria in(Object... o) {
 		if (o.length > 1 && o[1] instanceof Collection) {
-			throw new InvalidMongoDbApiUsageException(
-					"You can only pass in one argument of type " + o[1].getClass().getName());
+			throw new InvalidMongoDbApiUsageException("You can only pass in one argument of type "
+					+ o[1].getClass().getName());
 		}
 		criteria.put("$in", Arrays.asList(o));
 		return this;
@@ -498,6 +523,20 @@ public Criteria elemMatch(Criteria c) {
 		return this;
 	}
 
+	/**
+	 * Creates a criterion using the given object as a pattern.
+	 * 
+	 * @param sample
+	 * @return
+	 * @since 1.8
+	 */
+	public Criteria alike(Example<?> sample) {
+
+		criteria.put("$sample", sample);
+		this.criteriaChain.add(this);
+		return this;
+	}
+
 	/**
 	 * Creates an 'or' criteria using the $or operator for all of the provided criteria
 	 * <p>
@@ -543,8 +582,8 @@ public Criteria andOperator(Criteria... criteria) {
 	private Criteria registerCriteriaChainElement(Criteria criteria) {
 
 		if (lastOperatorWasNot()) {
-			throw new IllegalArgumentException(
-					"operator $not is not allowed around criteria chain element: " + criteria.getCriteriaObject());
+			throw new IllegalArgumentException("operator $not is not allowed around criteria chain element: "
+					+ criteria.getCriteriaObject());
 		} else {
 			criteriaChain.add(criteria);
 		}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/MongoRegexCreator.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.query;
+
+import java.util.regex.Pattern;
+
+import org.springframework.data.repository.query.parser.Part.Type;
+import org.springframework.util.ObjectUtils;
+
+/**
+ * @author Christoph Strobl
+ * @since 1.8
+ */
+public enum MongoRegexCreator {
+
+	INSTANCE;
+
+	private static final Pattern PUNCTATION_PATTERN = Pattern.compile("\\p{Punct}");
+
+	/**
+	 * Creates a regular expression String to be used with {@code $regex}.
+	 * 
+	 * @param source the plain String
+	 * @param type
+	 * @return {@literal source} when {@literal source} or {@literal type} is {@literal null}.
+	 */
+	public String toRegularExpression(String source, Type type) {
+
+		if (type == null || source == null) {
+			return source;
+		}
+
+		String regex = prepareAndEscapeStringBeforeApplyingLikeRegex(source, type);
+
+		switch (type) {
+			case STARTING_WITH:
+				regex = "^" + regex;
+				break;
+			case ENDING_WITH:
+				regex = regex + "$";
+				break;
+			case CONTAINING:
+			case NOT_CONTAINING:
+				regex = ".*" + regex + ".*";
+				break;
+			case SIMPLE_PROPERTY:
+			case NEGATING_SIMPLE_PROPERTY:
+				regex = "^" + regex + "$";
+			default:
+		}
+
+		return regex;
+	}
+
+	private String prepareAndEscapeStringBeforeApplyingLikeRegex(String source, Type type) {
+
+		if (!ObjectUtils.nullSafeEquals(Type.LIKE, type)) {
+			return PUNCTATION_PATTERN.matcher(source).find() ? Pattern.quote(source) : source;
+		}
+
+		if (source.equals("*")) {
+			return ".*";
+		}
+
+		StringBuilder sb = new StringBuilder();
+
+		boolean leadingWildcard = source.startsWith("*");
+		boolean trailingWildcard = source.endsWith("*");
+
+		String valueToUse = source.substring(leadingWildcard ? 1 : 0,
+				trailingWildcard ? source.length() - 1 : source.length());
+
+		if (PUNCTATION_PATTERN.matcher(valueToUse).find()) {
+			valueToUse = Pattern.quote(valueToUse);
+		}
+
+		if (leadingWildcard) {
+			sb.append(".*");
+		}
+		sb.append(valueToUse);
+		if (trailingWildcard) {
+			sb.append(".*");
+		}
+
+		return sb.toString();
+	}
+
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/SerializationUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 the original author or authors.
+ * Copyright 2012-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,26 +16,92 @@
 package org.springframework.data.mongodb.core.query;
 
 import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Map.Entry;
 
 import org.springframework.core.convert.converter.Converter;
 
+import com.mongodb.BasicDBObject;
 import com.mongodb.DBObject;
 import com.mongodb.util.JSON;
 
 /**
  * Utility methods for JSON serialization.
  * 
  * @author Oliver Gierke
+ * @author Christoph Strobl
  */
 public abstract class SerializationUtils {
 
 	private SerializationUtils() {
 
 	}
 
+	/**
+	 * Flattens out a given {@link DBObject}.
+	 * 
+	 * <pre>
+	 * <code>
+	 * {
+	 *   _id : 1
+	 *   nested : { value : "conflux"}
+	 * }
+	 * </code>
+	 * will result in 
+	 * <code>
+	 * {
+	 *   _id : 1
+	 *   nested.value : "conflux"
+	 * }
+	 * </code>
+	 * </pre>
+	 * 
+	 * @param source can be {@literal null}.
+	 * @return {@link Collections#emptyMap()} when source is {@literal null}
+	 * @since 1.8
+	 */
+	public static Map<String, Object> flatMap(DBObject source) {
+
+		if (source == null) {
+			return Collections.emptyMap();
+		}
+
+		Map<String, Object> result = new HashMap<String, Object>();
+		toFlatMap("", source, result);
+		return result;
+	}
+
+	private static void toFlatMap(String currentPath, Object source, Map<String, Object> map) {
+
+		if (source instanceof BasicDBObject) {
+
+			BasicDBObject dbo = (BasicDBObject) source;
+			Iterator<Map.Entry<String, Object>> iter = dbo.entrySet().iterator();
+			String pathPrefix = currentPath.isEmpty() ? "" : currentPath + ".";
+
+			while (iter.hasNext()) {
+
+				Map.Entry<String, Object> entry = iter.next();
+
+				if (entry.getKey().startsWith("$")) {
+					if (map.containsKey(currentPath)) {
+						((BasicDBObject) map.get(currentPath)).put(entry.getKey(), entry.getValue());
+					} else {
+						map.put(currentPath, new BasicDBObject(entry.getKey(), entry.getValue()));
+					}
+				} else {
+
+					toFlatMap(pathPrefix + entry.getKey(), entry.getValue(), map);
+				}
+			}
+		} else {
+			map.put(currentPath, source);
+		}
+	}
+
 	/**
 	 * Serializes the given object into pseudo-JSON meaning it's trying to create a JSON representation as far as possible
 	 * but falling back to the given object's {@link Object#toString()} method if it's not serializable. Useful for

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/MongoRepository.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2014 the original author or authors.
+ * Copyright 2010-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,9 @@
 import java.io.Serializable;
 import java.util.List;
 
+import org.springframework.data.domain.Example;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.NoRepositoryBean;
 import org.springframework.data.repository.PagingAndSortingRepository;
@@ -71,4 +74,34 @@ public interface MongoRepository<T, ID extends Serializable> extends PagingAndSo
 	 * @since 1.7
 	 */
 	<S extends T> List<S> insert(Iterable<S> entities);
+
+	/**
+	 * Returns all instances of the type specified by the given {@link Example}.
+	 * 
+	 * @param example must not be {@literal null}.
+	 * @return
+	 * @since 1.8
+	 */
+	<S extends T> List<T> findAllByExample(Example<S> example);
+
+	/**
+	 * Returns all instances of the type specified by the given {@link Example}.
+	 * 
+	 * @param example must not be {@literal null}.
+	 * @param sort can be {@literal null}.
+	 * @return all entities sorted by the given options
+	 * @since 1.8
+	 */
+	<S extends T> List<T> findAllByExample(Example<S> example, Sort sort);
+
+	/**
+	 * Returns a {@link Page} of entities meeting the paging restriction specified by the given {@link Example} limited to
+	 * criteria provided in the {@code Pageable} object.
+	 * 
+	 * @param example must not be {@literal null}.
+	 * @param pageable can be {@literal null}.
+	 * @return a {@link Page} of entities
+	 * @since 1.8
+	 */
+	<S extends T> Page<T> findAllByExample(Example<S> example, Pageable pageable);
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/ConvertingParameterAccessor.java

@@ -21,6 +21,7 @@
 import java.util.Iterator;
 import java.util.List;
 
+import org.springframework.data.domain.Example;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Range;
 import org.springframework.data.domain.Sort;
@@ -132,6 +133,11 @@ public TextCriteria getFullText() {
 		return delegate.getFullText();
 	}
 
+	@Override
+	public Example<?> getSampleObject() {
+		return delegate.getSampleObject();
+	}
+
 	/**
 	 * Converts the given value with the underlying {@link MongoWriter}.
 	 * 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/MongoParameterAccessor.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.mongodb.repository.query;
 
+import org.springframework.data.domain.Example;
 import org.springframework.data.domain.Range;
 import org.springframework.data.geo.Distance;
 import org.springframework.data.geo.Point;
@@ -60,4 +61,12 @@ public interface MongoParameterAccessor extends ParameterAccessor {
 	 * @since 1.8
 	 */
 	Object[] getValues();
+
+	/**
+	 * Get the sample for query by example
+	 * 
+	 * @return
+	 * @since 1.8
+	 */
+	Example<?> getSampleObject();
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/MongoParameters.java

@@ -20,6 +20,7 @@
 import java.util.List;
 
 import org.springframework.core.MethodParameter;
+import org.springframework.data.domain.Example;
 import org.springframework.data.domain.Range;
 import org.springframework.data.geo.Distance;
 import org.springframework.data.geo.Point;
@@ -42,6 +43,7 @@ public class MongoParameters extends Parameters<MongoParameters, MongoParameter>
 	private final int rangeIndex;
 	private final int maxDistanceIndex;
 	private final Integer fullTextIndex;
+	private final int sampleObjectIndex;
 
 	private Integer nearIndex;
 
@@ -69,17 +71,20 @@ public MongoParameters(Method method, boolean isGeoNearMethod) {
 		} else if (this.nearIndex == null) {
 			this.nearIndex = -1;
 		}
+
+		this.sampleObjectIndex = parameterTypes.indexOf(Example.class);
 	}
 
 	private MongoParameters(List<MongoParameter> parameters, int maxDistanceIndex, Integer nearIndex,
-			Integer fullTextIndex, int rangeIndex) {
+			Integer fullTextIndex, int rangeIndex, int sampleObjectIndex) {
 
 		super(parameters);
 
 		this.nearIndex = nearIndex;
 		this.fullTextIndex = fullTextIndex;
 		this.maxDistanceIndex = maxDistanceIndex;
 		this.rangeIndex = rangeIndex;
+		this.sampleObjectIndex = sampleObjectIndex;
 	}
 
 	private final int getNearIndex(List<Class<?>> parameterTypes) {
@@ -182,13 +187,22 @@ public int getRangeIndex() {
 		return rangeIndex;
 	}
 
+	/**
+	 * @return
+	 * @since 1.8
+	 */
+	public int getSampleObjectParameterIndex() {
+		return sampleObjectIndex;
+	}
+
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.query.Parameters#createFrom(java.util.List)
 	 */
 	@Override
 	protected MongoParameters createFrom(List<MongoParameter> parameters) {
-		return new MongoParameters(parameters, this.maxDistanceIndex, this.nearIndex, this.fullTextIndex, this.rangeIndex);
+		return new MongoParameters(parameters, this.maxDistanceIndex, this.nearIndex, this.fullTextIndex, this.rangeIndex,
+				this.sampleObjectIndex);
 	}
 
 	private int getTypeIndex(List<TypeInformation<?>> parameterTypes, Class<?> type, Class<?> componentType) {
@@ -240,7 +254,7 @@ class MongoParameter extends Parameter {
 		@Override
 		public boolean isSpecialParameter() {
 			return super.isSpecialParameter() || Distance.class.isAssignableFrom(getType()) || isNearParameter()
-					|| TextCriteria.class.isAssignableFrom(getType());
+					|| TextCriteria.class.isAssignableFrom(getType()) || isExample();
 		}
 
 		private boolean isNearParameter() {
@@ -260,6 +274,10 @@ private boolean hasNearAnnotation() {
 			return parameter.getParameterAnnotation(Near.class) != null;
 		}
 
+		private boolean isExample() {
+			return Example.class.isAssignableFrom(getType());
+		}
+
 	}
 
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/MongoParametersParameterAccessor.java

@@ -18,6 +18,7 @@
 import java.util.Arrays;
 import java.util.List;
 
+import org.springframework.data.domain.Example;
 import org.springframework.data.domain.Range;
 import org.springframework.data.geo.Distance;
 import org.springframework.data.geo.Point;
@@ -125,9 +126,15 @@ protected TextCriteria potentiallyConvertFullText(Object fullText) {
 			return ((TextCriteria) fullText);
 		}
 
-		throw new IllegalArgumentException(
-				String.format("Expected full text parameter to be one of String, Term or TextCriteria but found %s.",
-						ClassUtils.getShortName(fullText.getClass())));
+		throw new IllegalArgumentException(String.format(
+				"Expected full text parameter to be one of String, Term or TextCriteria but found %s.",
+				ClassUtils.getShortName(fullText.getClass())));
+	}
+
+	public Example<?> getSampleObject() {
+
+		int index = method.getParameters().getSampleObjectParameterIndex();
+		return index >= 0 ? (Example<?>) getValue(index) : null;
 	}
 
 	/* 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/MongoQueryCreator.java

@@ -38,6 +38,7 @@
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
 import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.CriteriaDefinition;
+import org.springframework.data.mongodb.core.query.MongoRegexCreator;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.repository.query.ConvertingParameterAccessor.PotentiallyConvertingIterator;
 import org.springframework.data.repository.query.parser.AbstractQueryCreator;
@@ -46,7 +47,6 @@
 import org.springframework.data.repository.query.parser.Part.Type;
 import org.springframework.data.repository.query.parser.PartTree;
 import org.springframework.util.Assert;
-import org.springframework.util.ObjectUtils;
 
 /**
  * Custom query creator to create Mongo criterias.
@@ -151,7 +151,20 @@ protected Criteria or(Criteria base, Criteria criteria) {
 	@Override
 	protected Query complete(Criteria criteria, Sort sort) {
 
-		Query query = (criteria == null ? new Query() : new Query(criteria)).with(sort);
+		Criteria toUse = null;
+		if (accessor.getSampleObject() != null) {
+			toUse = new Criteria().alike(accessor.getSampleObject());
+		}
+
+		if (criteria != null) {
+			if (toUse == null) {
+				toUse = criteria;
+			} else {
+				toUse.andOperator(criteria);
+			}
+		}
+
+		Query query = (toUse == null ? new Query() : new Query(toUse)).with(sort);
 
 		if (LOG.isDebugEnabled()) {
 			LOG.debug("Created query " + query);
@@ -285,8 +298,8 @@ private Criteria createLikeRegexCriteriaOrThrow(Part part, MongoPersistentProper
 
 			case ALWAYS:
 				if (path.getType() != String.class) {
-					throw new IllegalArgumentException(
-							String.format("Part %s must be of type String but was %s", path, path.getType()));
+					throw new IllegalArgumentException(String.format("Part %s must be of type String but was %s", path,
+							path.getType()));
 				}
 				// fall-through
 
@@ -372,8 +385,8 @@ private <T> T nextAs(Iterator<Object> iterator, Class<T> type) {
 			return (T) parameter;
 		}
 
-		throw new IllegalArgumentException(
-				String.format("Expected parameter type of %s but got %s!", type, parameter.getClass()));
+		throw new IllegalArgumentException(String.format("Expected parameter type of %s but got %s!", type,
+				parameter.getClass()));
 	}
 
 	private Object[] nextAsArray(Iterator<Object> iterator) {
@@ -390,61 +403,7 @@ private Object[] nextAsArray(Iterator<Object> iterator) {
 	}
 
 	private String toLikeRegex(String source, Part part) {
-
-		Type type = part.getType();
-		String regex = prepareAndEscapeStringBeforeApplyingLikeRegex(source, part);
-
-		switch (type) {
-			case STARTING_WITH:
-				regex = "^" + regex;
-				break;
-			case ENDING_WITH:
-				regex = regex + "$";
-				break;
-			case CONTAINING:
-			case NOT_CONTAINING:
-				regex = ".*" + regex + ".*";
-				break;
-			case SIMPLE_PROPERTY:
-			case NEGATING_SIMPLE_PROPERTY:
-				regex = "^" + regex + "$";
-			default:
-		}
-
-		return regex;
-	}
-
-	private String prepareAndEscapeStringBeforeApplyingLikeRegex(String source, Part qpart) {
-
-		if (!ObjectUtils.nullSafeEquals(Type.LIKE, qpart.getType())) {
-			return PUNCTATION_PATTERN.matcher(source).find() ? Pattern.quote(source) : source;
-		}
-
-		if ("*".equals(source)) {
-			return ".*";
-		}
-
-		StringBuilder sb = new StringBuilder();
-
-		boolean leadingWildcard = source.startsWith("*");
-		boolean trailingWildcard = source.endsWith("*");
-
-		String valueToUse = source.substring(leadingWildcard ? 1 : 0,
-				trailingWildcard ? source.length() - 1 : source.length());
-
-		if (PUNCTATION_PATTERN.matcher(valueToUse).find()) {
-			valueToUse = Pattern.quote(valueToUse);
-		}
-
-		if (leadingWildcard) {
-			sb.append(".*");
-		}
-		sb.append(valueToUse);
-		if (trailingWildcard) {
-			sb.append(".*");
-		}
-
-		return sb.toString();
+		return MongoRegexCreator.INSTANCE.toRegularExpression(source, part.getType());
 	}
 
 	private boolean isSpherical(MongoPersistentProperty property) {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/SimpleMongoRepository.java

@@ -25,6 +25,7 @@
 import java.util.List;
 import java.util.Set;
 
+import org.springframework.data.domain.Example;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.Pageable;
@@ -259,6 +260,57 @@ public <S extends T> List<S> insert(Iterable<S> entities) {
 		return list;
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.repository.MongoRepository#findAllByExample(org.springframework.data.domain.Example, org.springframework.data.domain.Pageable)
+	 */
+	@Override
+	public <S extends T> Page<T> findAllByExample(Example<S> example, Pageable pageable) {
+
+		Assert.notNull(example, "Sample must not be null!");
+
+		Query q = new Query(new Criteria().alike(example)).with(pageable);
+
+		long count = mongoOperations.count(q, entityInformation.getJavaType(), entityInformation.getCollectionName());
+		if (count == 0) {
+			return new PageImpl<T>(Collections.<T> emptyList());
+		}
+		return new PageImpl<T>(mongoOperations.find(q, entityInformation.getJavaType(),
+				entityInformation.getCollectionName()), pageable, count);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.repository.MongoRepository#findAllByExample(org.springframework.data.domain.Example, org.springframework.data.domain.Sort)
+	 */
+	@Override
+	public <S extends T> List<T> findAllByExample(Example<S> example, Sort sort) {
+
+		Assert.notNull(example, "Sample must not be null!");
+
+		Query q = new Query(new Criteria().alike(example));
+
+		if (sort != null) {
+			q.with(sort);
+		}
+
+		return findAll(q);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.repository.MongoRepository#findAllByExample(org.springframework.data.domain.Example)
+	 */
+	@Override
+	public <S extends T> List<T> findAllByExample(Example<S> example) {
+
+		Assert.notNull(example, "Sample must not be null!");
+
+		Query q = new Query(new Criteria().alike(example));
+
+		return findAll(q);
+	}
+
 	private List<T> findAll(Query query) {
 
 		if (query == null) {
@@ -291,4 +343,5 @@ private static <T> List<T> convertIterableToList(Iterable<T> entities) {
 	private static int tryDetermineRealSizeOrReturn(Iterable<?> iterable, int defaultSize) {
 		return iterable == null ? 0 : (iterable instanceof Collection) ? ((Collection<?>) iterable).size() : defaultSize;
 	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 the original author or authors.
+ * Copyright 2012-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,18 +20,24 @@
 import static org.springframework.data.mongodb.core.query.SerializationUtils.*;
 
 import java.util.Arrays;
+import java.util.Map;
 
 import org.hamcrest.Matcher;
+import org.hamcrest.collection.IsMapContaining;
+import org.hamcrest.core.Is;
 import org.junit.Test;
 import org.springframework.data.mongodb.core.query.SerializationUtils;
 
+import com.mongodb.BasicDBList;
 import com.mongodb.BasicDBObject;
+import com.mongodb.BasicDBObjectBuilder;
 import com.mongodb.DBObject;
 
 /**
  * Unit tests for {@link SerializationUtils}.
  * 
  * @author Oliver Gierke
+ * @author Christoph Strobl
  */
 public class SerializationUtilsUnitTests {
 
@@ -60,6 +66,74 @@ public void writesCollection() {
 		assertThat(serializeToJsonSafely(dbObject), is(expectedOutput));
 	}
 
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void flatMapShouldFlatOutNestedStructureCorrectly() {
+
+		DBObject dbo = new BasicDBObjectBuilder().add("_id", 1).add("nested", new BasicDBObject("value", "conflux")).get();
+
+		assertThat(flatMap(dbo), IsMapContaining.<String, Object> hasEntry("_id", 1));
+		assertThat(flatMap(dbo), IsMapContaining.<String, Object> hasEntry("nested.value", "conflux"));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void flatMapShouldFlatOutNestedStructureWithListCorrectly() {
+
+		BasicDBList dbl = new BasicDBList();
+		dbl.addAll(Arrays.asList("nightwielder", "calamity"));
+
+		DBObject dbo = new BasicDBObjectBuilder().add("_id", 1).add("nested", new BasicDBObject("value", dbl)).get();
+
+		assertThat(flatMap(dbo), IsMapContaining.<String, Object> hasEntry("_id", 1));
+		assertThat(flatMap(dbo), IsMapContaining.<String, Object> hasEntry("nested.value", dbl));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void flatMapShouldLeaveKeywordsUntouched() {
+
+		DBObject dbo = new BasicDBObjectBuilder().add("_id", 1).add("nested", new BasicDBObject("$regex", "^conflux$"))
+				.get();
+
+		Map<String, Object> map = flatMap(dbo);
+
+		assertThat(map, IsMapContaining.<String, Object> hasEntry("_id", 1));
+		assertThat(map.get("nested"), notNullValue());
+		assertThat(((Map<String, Object>) map.get("nested")).get("$regex"), Is.<Object> is("^conflux$"));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void flatMapSouldAppendCommandsCorrectly() {
+
+		DBObject dbo = new BasicDBObjectBuilder().add("_id", 1)
+				.add("nested", new BasicDBObjectBuilder().add("$regex", "^conflux$").add("$options", "i").get()).get();
+
+		Map<String, Object> map = flatMap(dbo);
+
+		assertThat(map, IsMapContaining.<String, Object> hasEntry("_id", 1));
+		assertThat(map.get("nested"), notNullValue());
+		assertThat(((Map<String, Object>) map.get("nested")).get("$regex"), Is.<Object> is("^conflux$"));
+		assertThat(((Map<String, Object>) map.get("nested")).get("$options"), Is.<Object> is("i"));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void flatMapShouldReturnEmptyMapWhenSourceIsNull() {
+		assertThat(flatMap(null).isEmpty(), is(true));
+	}
+
 	static class Complex {
 
 	}

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

@@ -29,6 +29,7 @@
 import java.util.Map;
 
 import org.bson.types.ObjectId;
+import org.hamcrest.core.Is;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -791,6 +792,8 @@ public void intersectsShouldUseGeoJsonRepresentationCorrectly() {
 	}
 
 	/**
+	 * <<<<<<< HEAD
+	 * 
 	 * @see DATAMONGO-1269
 	 */
 	@Test
@@ -818,6 +821,40 @@ public void mappingShouldRetainNumericPositionInList() {
 		assertThat(dbo.containsField("list.1.stringProperty"), is(true));
 	}
 
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void exampleShouldBeMappedCorrectly() {
+
+		Foo probe = new Foo();
+		probe.embedded = new EmbeddedClass();
+		probe.embedded.id = "conflux";
+
+		Query query = query(byExample(probe));
+
+		DBObject dbo = mapper.getMappedObject(query.getQueryObject(), context.getPersistentEntity(Foo.class));
+
+		assertThat(dbo, is(new BasicDBObjectBuilder().add("embedded._id", "conflux").get()));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void exampleShouldBeMappedCorrectlyWhenContainingLegacyPoint() {
+
+		ClassWithGeoTypes probe = new ClassWithGeoTypes();
+		probe.legacyPoint = new Point(10D, 20D);
+
+		Query query = query(byExample(probe));
+
+		DBObject dbo = mapper.getMappedObject(query.getQueryObject(), context.getPersistentEntity(WithDBRef.class));
+
+		assertThat(dbo.get("legacyPoint.x"), Is.<Object> is(10D));
+		assertThat(dbo.get("legacyPoint.y"), Is.<Object> is(20D));
+	}
+
 	@Document
 	public class Foo {
 		@Id private ObjectId id;

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

@@ -0,0 +1,174 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.temp;
+
+import java.net.UnknownHostException;
+import java.util.List;
+
+import org.hamcrest.core.Is;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.domain.Example;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.core.mapping.Document;
+import org.springframework.data.mongodb.core.mapping.Field;
+import org.springframework.data.mongodb.core.query.Criteria;
+import org.springframework.data.mongodb.core.query.Query;
+
+import com.mongodb.MongoClient;
+
+public class QueryByExampleTests {
+
+	MongoTemplate template;
+
+	@Before
+	public void setUp() throws UnknownHostException {
+
+		template = new MongoTemplate(new MongoClient(), "query-by-example");
+		template.remove(new Query(), Person.class);
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findByExampleShouldWorkForSimpleProperty() {
+
+		init();
+
+		Person sample = new Person();
+		sample.lastname = "stark";
+
+		List<Person> result = template.findByExample(sample);
+		Assert.assertThat(result.size(), Is.is(2));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findByExampleShouldWorkForMultipleProperties() {
+
+		init();
+
+		Person sample = new Person();
+		sample.lastname = "stark";
+		sample.firstname = "arya";
+
+		List<Person> result = template.findByExample(sample);
+		Assert.assertThat(result.size(), Is.is(1));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findByExampleShouldWorkForIdProperty() {
+
+		init();
+
+		Person p4 = new Person();
+		template.save(p4);
+
+		Person sample = new Person();
+		sample.id = p4.id;
+
+		List<Person> result = template.findByExample(sample);
+		Assert.assertThat(result.size(), Is.is(1));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findByExampleShouldReturnEmptyListIfNotMatching() {
+
+		init();
+
+		Person sample = new Person();
+		sample.firstname = "jon";
+		sample.firstname = "stark";
+
+		List<Person> result = template.findByExample(sample);
+		Assert.assertThat(result.size(), Is.is(0));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findByExampleShouldReturnEverythingWhenSampleIsEmpty() {
+
+		init();
+
+		Person sample = new Person();
+
+		List<Person> result = template.findByExample(sample);
+		Assert.assertThat(result.size(), Is.is(3));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findByExampleWithCriteria() {
+
+		init();
+
+		Person sample = new Person();
+		sample.lastname = "stark";
+
+		Query query = new Query(new Criteria().alike(new Example<Person>(sample)).and("firstname").regex("^ary*"));
+
+		List<Person> result = template.find(query, Person.class);
+		Assert.assertThat(result.size(), Is.is(1));
+	}
+
+	public void init() {
+
+		Person p1 = new Person();
+		p1.firstname = "bran";
+		p1.lastname = "stark";
+
+		Person p2 = new Person();
+		p2.firstname = "jon";
+		p2.lastname = "snow";
+
+		Person p3 = new Person();
+		p3.firstname = "arya";
+		p3.lastname = "stark";
+
+		template.save(p1);
+		template.save(p2);
+		template.save(p3);
+	}
+
+	@Document(collection = "dramatis-personae")
+	static class Person {
+
+		@Id String id;
+		String firstname;
+
+		@Field("last_name") String lastname;
+
+		@Override
+		public String toString() {
+			return "Person [id=" + id + ", firstname=" + firstname + ", lastname=" + lastname + "]";
+		}
+	}
+}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/temp/QueryByExampleTests.java

@@ -28,12 +28,15 @@
 import java.util.stream.Stream;
 
 import org.hamcrest.Matchers;
+import org.hamcrest.core.Is;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.dao.DuplicateKeyException;
+import org.springframework.data.domain.Example;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Range;
@@ -55,6 +58,7 @@
 import org.springframework.data.mongodb.repository.SampleEvaluationContextExtension.SampleSecurityContextHolder;
 import org.springframework.data.querydsl.QSort;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.util.ReflectionTestUtils;
 
 /**
  * Base class for tests for {@link PersonRepository}.
@@ -175,8 +179,8 @@ public void findsPagedPersons() throws Exception {
 	@Test
 	public void executesPagedFinderCorrectly() throws Exception {
 
-		Page<Person> page = repository.findByLastnameLike("*a*",
-				new PageRequest(0, 2, Direction.ASC, "lastname", "firstname"));
+		Page<Person> page = repository.findByLastnameLike("*a*", new PageRequest(0, 2, Direction.ASC, "lastname",
+				"firstname"));
 		assertThat(page.isFirst(), is(true));
 		assertThat(page.isLast(), is(false));
 		assertThat(page.getNumberOfElements(), is(2));
@@ -186,8 +190,8 @@ public void executesPagedFinderCorrectly() throws Exception {
 	@Test
 	public void executesPagedFinderWithAnnotatedQueryCorrectly() throws Exception {
 
-		Page<Person> page = repository.findByLastnameLikeWithPageable(".*a.*",
-				new PageRequest(0, 2, Direction.ASC, "lastname", "firstname"));
+		Page<Person> page = repository.findByLastnameLikeWithPageable(".*a.*", new PageRequest(0, 2, Direction.ASC,
+				"lastname", "firstname"));
 		assertThat(page.isFirst(), is(true));
 		assertThat(page.isLast(), is(false));
 		assertThat(page.getNumberOfElements(), is(2));
@@ -311,8 +315,8 @@ public void findsPeopleByLocationWithinPolygon() {
 	@Test
 	public void findsPagedPeopleByPredicate() throws Exception {
 
-		Page<Person> page = repository.findAll(person.lastname.contains("a"),
-				new PageRequest(0, 2, Direction.ASC, "lastname"));
+		Page<Person> page = repository.findAll(person.lastname.contains("a"), new PageRequest(0, 2, Direction.ASC,
+				"lastname"));
 		assertThat(page.isFirst(), is(true));
 		assertThat(page.isLast(), is(false));
 		assertThat(page.getNumberOfElements(), is(2));
@@ -398,8 +402,8 @@ public void executesGeoNearQueryForResultsCorrectly() {
 		dave.setLocation(point);
 		repository.save(dave);
 
-		GeoResults<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73),
-				new Distance(2000, Metrics.KILOMETERS));
+		GeoResults<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73), new Distance(2000,
+				Metrics.KILOMETERS));
 		assertThat(results.getContent().isEmpty(), is(false));
 	}
 
@@ -410,8 +414,8 @@ public void executesGeoPageQueryForResultsCorrectly() {
 		dave.setLocation(point);
 		repository.save(dave);
 
-		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73),
-				new Distance(2000, Metrics.KILOMETERS), new PageRequest(0, 20));
+		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73), new Distance(2000,
+				Metrics.KILOMETERS), new PageRequest(0, 20));
 		assertThat(results.getContent().isEmpty(), is(false));
 
 		// DATAMONGO-607
@@ -621,8 +625,8 @@ public void executesGeoPageQueryForWithPageRequestForPageInBetween() {
 
 		repository.save(Arrays.asList(dave, oliver, carter, boyd, leroi));
 
-		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73),
-				new Distance(2000, Metrics.KILOMETERS), new PageRequest(1, 2));
+		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73), new Distance(2000,
+				Metrics.KILOMETERS), new PageRequest(1, 2));
 
 		assertThat(results.getContent().isEmpty(), is(false));
 		assertThat(results.getNumberOfElements(), is(2));
@@ -646,8 +650,8 @@ public void executesGeoPageQueryForWithPageRequestForPageAtTheEnd() {
 
 		repository.save(Arrays.asList(dave, oliver, carter));
 
-		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73),
-				new Distance(2000, Metrics.KILOMETERS), new PageRequest(1, 2));
+		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73), new Distance(2000,
+				Metrics.KILOMETERS), new PageRequest(1, 2));
 		assertThat(results.getContent().isEmpty(), is(false));
 		assertThat(results.getNumberOfElements(), is(1));
 		assertThat(results.isFirst(), is(false));
@@ -665,8 +669,8 @@ public void executesGeoPageQueryForWithPageRequestForJustOneElement() {
 		dave.setLocation(point);
 		repository.save(dave);
 
-		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73),
-				new Distance(2000, Metrics.KILOMETERS), new PageRequest(0, 2));
+		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73), new Distance(2000,
+				Metrics.KILOMETERS), new PageRequest(0, 2));
 
 		assertThat(results.getContent().isEmpty(), is(false));
 		assertThat(results.getNumberOfElements(), is(1));
@@ -684,8 +688,8 @@ public void executesGeoPageQueryForWithPageRequestForJustOneElementEmptyPage() {
 		dave.setLocation(new Point(-73.99171, 40.738868));
 		repository.save(dave);
 
-		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73),
-				new Distance(2000, Metrics.KILOMETERS), new PageRequest(1, 2));
+		GeoPage<Person> results = repository.findByLocationNear(new Point(-73.99, 40.73), new Distance(2000,
+				Metrics.KILOMETERS), new PageRequest(1, 2));
 
 		assertThat(results.getContent().isEmpty(), is(true));
 		assertThat(results.getNumberOfElements(), is(0));
@@ -935,8 +939,8 @@ public void findByCustomQueryLastnameAndStreetInList() {
 	@Test
 	public void shouldLimitCollectionQueryToMaxResultsWhenPresent() {
 
-		repository.save(Arrays.asList(new Person("Bob-1", "Dylan"), new Person("Bob-2", "Dylan"),
-				new Person("Bob-3", "Dylan"), new Person("Bob-4", "Dylan"), new Person("Bob-5", "Dylan")));
+		repository.save(Arrays.asList(new Person("Bob-1", "Dylan"), new Person("Bob-2", "Dylan"), new Person("Bob-3",
+				"Dylan"), new Person("Bob-4", "Dylan"), new Person("Bob-5", "Dylan")));
 		List<Person> result = repository.findTop3ByLastnameStartingWith("Dylan");
 		assertThat(result.size(), is(3));
 	}
@@ -947,8 +951,8 @@ public void shouldLimitCollectionQueryToMaxResultsWhenPresent() {
 	@Test
 	public void shouldNotLimitPagedQueryWhenPageRequestWithinBounds() {
 
-		repository.save(Arrays.asList(new Person("Bob-1", "Dylan"), new Person("Bob-2", "Dylan"),
-				new Person("Bob-3", "Dylan"), new Person("Bob-4", "Dylan"), new Person("Bob-5", "Dylan")));
+		repository.save(Arrays.asList(new Person("Bob-1", "Dylan"), new Person("Bob-2", "Dylan"), new Person("Bob-3",
+				"Dylan"), new Person("Bob-4", "Dylan"), new Person("Bob-5", "Dylan")));
 		Page<Person> result = repository.findTop3ByLastnameStartingWith("Dylan", new PageRequest(0, 2));
 		assertThat(result.getContent().size(), is(2));
 	}
@@ -959,8 +963,8 @@ public void shouldNotLimitPagedQueryWhenPageRequestWithinBounds() {
 	@Test
 	public void shouldLimitPagedQueryWhenPageRequestExceedsUpperBoundary() {
 
-		repository.save(Arrays.asList(new Person("Bob-1", "Dylan"), new Person("Bob-2", "Dylan"),
-				new Person("Bob-3", "Dylan"), new Person("Bob-4", "Dylan"), new Person("Bob-5", "Dylan")));
+		repository.save(Arrays.asList(new Person("Bob-1", "Dylan"), new Person("Bob-2", "Dylan"), new Person("Bob-3",
+				"Dylan"), new Person("Bob-4", "Dylan"), new Person("Bob-5", "Dylan")));
 		Page<Person> result = repository.findTop3ByLastnameStartingWith("Dylan", new PageRequest(1, 2));
 		assertThat(result.getContent().size(), is(1));
 	}
@@ -971,8 +975,8 @@ public void shouldLimitPagedQueryWhenPageRequestExceedsUpperBoundary() {
 	@Test
 	public void shouldReturnEmptyWhenPageRequestedPageIsTotallyOutOfScopeForLimit() {
 
-		repository.save(Arrays.asList(new Person("Bob-1", "Dylan"), new Person("Bob-2", "Dylan"),
-				new Person("Bob-3", "Dylan"), new Person("Bob-4", "Dylan"), new Person("Bob-5", "Dylan")));
+		repository.save(Arrays.asList(new Person("Bob-1", "Dylan"), new Person("Bob-2", "Dylan"), new Person("Bob-3",
+				"Dylan"), new Person("Bob-4", "Dylan"), new Person("Bob-5", "Dylan")));
 		Page<Person> result = repository.findTop3ByLastnameStartingWith("Dylan", new PageRequest(2, 2));
 		assertThat(result.getContent().size(), is(0));
 	}
@@ -1221,4 +1225,41 @@ public void shouldFindByFirstnameForSpELExpressionWithParameterVariableOnly() {
 		assertThat(users, hasSize(1));
 		assertThat(users.get(0), is(dave));
 	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findByExampleShouldResolveStuffCorrectly() {
+
+		Person sample = new Person();
+		sample.setLastname("Matthews");
+
+		// needed to tweak stuff a bit since some field are automatically set - so we need to undo this
+		ReflectionTestUtils.setField(sample, "id", null);
+		ReflectionTestUtils.setField(sample, "createdAt", null);
+		ReflectionTestUtils.setField(sample, "email", null);
+
+		Page<Person> result = repository.findAllByExample(new Example<Person>(sample), new PageRequest(0, 10));
+		Assert.assertThat(result.getNumberOfElements(), Is.is(2));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldResolveStuffCorrectly() {
+
+		Person sample = new Person();
+		sample.setLastname("Matthews");
+
+		// needed to tweak stuff a bit since some field are automatically set - so we need to undo this
+		ReflectionTestUtils.setField(sample, "id", null);
+		ReflectionTestUtils.setField(sample, "createdAt", null);
+		ReflectionTestUtils.setField(sample, "email", null);
+
+		List<Person> result = repository.findAllByExample(new Example<Person>(sample));
+		Assert.assertThat(result.size(), Is.is(2));
+	}
+
 }

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/AbstractPersonRepositoryIntegrationTests.java

@@ -27,8 +27,7 @@
 @Document
 public abstract class Contact {
 
-	@Id
-	protected final String id;
+	@Id protected String id;
 
 	public Contact() {
 		this.id = new ObjectId().toString();

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/Contact.java

@@ -334,22 +334,23 @@ public interface PersonRepository extends MongoRepository<Person, String>, Query
 	 */
 	@Query("{ firstname : { $in : ?0 }}")
 	Stream<Person> findByCustomQueryWithStreamingCursorByFirstnames(List<String> firstnames);
-	
+
 	/**
 	 * @see DATAMONGO-990
 	 */
 	@Query("{ firstname : ?#{[0]}}")
 	List<Person> findWithSpelByFirstnameForSpELExpressionWithParameterIndexOnly(String firstname);
-	
+
 	/**
 	 * @see DATAMONGO-990
 	 */
 	@Query("{ firstname : ?#{[0]}, email: ?#{principal.email} }")
 	List<Person> findWithSpelByFirstnameAndCurrentUserWithCustomQuery(String firstname);
-	
+
 	/**
 	 * @see DATAMONGO-990
 	 */
 	@Query("{ firstname : :#{#firstname}}")
 	List<Person> findWithSpelByFirstnameForSpELExpressionWithParameterVariableOnly(@Param("firstname") String firstname);
+
 }

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/PersonRepository.java

@@ -18,6 +18,7 @@
 import java.util.Arrays;
 import java.util.Iterator;
 
+import org.springframework.data.domain.Example;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Range;
 import org.springframework.data.domain.Sort;
@@ -147,4 +148,13 @@ public Object[] getValues() {
 	public Class<?> getDynamicProjection() {
 		return null;
 	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.repository.query.MongoParameterAccessor#getSampleObject()
+	 */
+	@Override
+	public Example<?> getSampleObject() {
+		return null;
+	}
 }

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/query/StubParameterAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2014 the original author or authors.
+ * Copyright 2010-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,16 +31,26 @@
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Example;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.geo.Point;
 import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.core.geo.GeoJsonPoint;
+import org.springframework.data.mongodb.core.mapping.Document;
+import org.springframework.data.mongodb.repository.Address;
 import org.springframework.data.mongodb.repository.Person;
 import org.springframework.data.mongodb.repository.Person.Sex;
+import org.springframework.data.mongodb.repository.User;
 import org.springframework.data.mongodb.repository.query.MongoEntityInformation;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.util.ReflectionTestUtils;
 
 /**
  * @author <a href="mailto:kowsercse@gmail.com">A. B. M. Kowser</a>
  * @author Thomas Darimont
+ * @author Christoph Strobl
  */
 @RunWith(SpringJUnit4ClassRunner.class)
 @ContextConfiguration("classpath:infrastructure.xml")
@@ -160,6 +170,224 @@ public void shouldInsertMutlipleFromSet() {
 		assertThatAllReferencePersonsWereStoredCorrectly(idToPerson, saved);
 	}
 
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findByExampleShouldLookUpEntriesCorrectly() {
+
+		Person sample = new Person();
+		sample.setLastname("Matthews");
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		Page<Person> result = repository.findAllByExample(new Example<Person>(sample), new PageRequest(0, 10));
+
+		assertThat(result.getContent(), hasItems(dave, oliver));
+		assertThat(result.getContent(), hasSize(2));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldLookUpEntriesCorrectly() {
+
+		Person sample = new Person();
+		sample.setLastname("Matthews");
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(new Example<Person>(sample));
+
+		assertThat(result, hasItems(dave, oliver));
+		assertThat(result, hasSize(2));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldLookUpEntriesCorrectlyWhenUsingNestedObject() {
+
+		dave.setAddress(new Address("1600 Pennsylvania Ave NW", "20500", "Washington"));
+		repository.save(dave);
+
+		oliver.setAddress(new Address("East Capitol St NE & First St SE", "20004", "Washington"));
+		repository.save(oliver);
+
+		Person sample = new Person();
+		sample.setAddress(dave.getAddress());
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(new Example<Person>(sample));
+
+		assertThat(result, hasItem(dave));
+		assertThat(result, hasSize(1));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldLookUpEntriesCorrectlyWhenUsingPartialNestedObject() {
+
+		dave.setAddress(new Address("1600 Pennsylvania Ave NW", "20500", "Washington"));
+		repository.save(dave);
+
+		oliver.setAddress(new Address("East Capitol St NE & First St SE", "20004", "Washington"));
+		repository.save(oliver);
+
+		Person sample = new Person();
+		sample.setAddress(new Address(null, null, "Washington"));
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(new Example<Person>(sample));
+
+		assertThat(result, hasItems(dave, oliver));
+		assertThat(result, hasSize(2));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldNotFindEntriesWhenUsingPartialNestedObjectInStrictMode() {
+
+		dave.setAddress(new Address("1600 Pennsylvania Ave NW", "20500", "Washington"));
+		repository.save(dave);
+
+		Person sample = new Person();
+		sample.setAddress(new Address(null, null, "Washington"));
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(Example.newExampleOf(sample).includeNullValues().get());
+
+		assertThat(result, empty());
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldLookUpEntriesCorrectlyWhenUsingNestedObjectInStrictMode() {
+
+		dave.setAddress(new Address("1600 Pennsylvania Ave NW", "20500", "Washington"));
+		repository.save(dave);
+
+		Person sample = new Person();
+		sample.setAddress(dave.getAddress());
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(Example.newExampleOf(sample).includeNullValues().get());
+
+		assertThat(result, hasItem(dave));
+		assertThat(result, hasSize(1));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldRespectStringMatchMode() {
+
+		Person sample = new Person();
+		sample.setLastname("Mat");
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(Example.newExampleOf(sample).matchStringsStartingWith().get());
+
+		assertThat(result, hasItems(dave, oliver));
+		assertThat(result, hasSize(2));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldResolveDbRefCorrectly() {
+
+		User user = new User();
+		user.setId("c0nf1ux");
+		user.setUsername("conflux");
+		template.save(user);
+
+		Person megan = new Person("megan", "tarash");
+		megan.setCreator(user);
+
+		repository.save(megan);
+
+		Person sample = new Person();
+		sample.setCreator(user);
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(new Example<Person>(sample));
+
+		assertThat(result, hasItem(megan));
+		assertThat(result, hasSize(1));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldResolveLegacyCoordinatesCorrectly() {
+
+		Person megan = new Person("megan", "tarash");
+		megan.setLocation(new Point(41.85003D, -87.65005D));
+
+		repository.save(megan);
+
+		Person sample = new Person();
+		sample.setLocation(megan.getLocation());
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(new Example<Person>(sample));
+
+		assertThat(result, hasItem(megan));
+		assertThat(result, hasSize(1));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldResolveGeoJsonCoordinatesCorrectly() {
+
+		Person megan = new Person("megan", "tarash");
+		megan.setLocation(new GeoJsonPoint(41.85003D, -87.65005D));
+
+		repository.save(megan);
+
+		Person sample = new Person();
+		sample.setLocation(megan.getLocation());
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(new Example<Person>(sample));
+
+		assertThat(result, hasItem(megan));
+		assertThat(result, hasSize(1));
+	}
+
+	/**
+	 * @see DATAMONGO-1245
+	 */
+	@Test
+	public void findAllByExampleShouldProcessInheritanceCorrectly() {
+
+		PersonExtended sample = new PersonExtended() {};
+		sample.setLastname("Matthews");
+		trimDomainType(sample, "id", "createdAt", "email");
+
+		List<Person> result = repository.findAllByExample(new Example<PersonExtended>(sample));
+
+		assertThat(result, hasItems(dave, oliver));
+		assertThat(result, hasSize(2));
+	}
+
+	@Document(collection = "customizedPerson")
+	static class PersonExtended extends Person {
+
+	}
+
 	private void assertThatAllReferencePersonsWereStoredCorrectly(Map<String, Person> references, List<Person> saved) {
 
 		for (Person person : saved) {
@@ -168,6 +396,13 @@ private void assertThatAllReferencePersonsWereStoredCorrectly(Map<String, Person
 		}
 	}
 
+	private void trimDomainType(Object source, String... attributes) {
+
+		for (String attribute : attributes) {
+			ReflectionTestUtils.setField(source, attribute, null);
+		}
+	}
+
 	private static class CustomizedPersonInformation implements MongoEntityInformation<Person, String> {
 
 		@Override