DATAMONGO-347 - Derived repository queries now correctly resolve referenced DBRef properties.

Added toDBRef(…) method to MongoWriter to be able to create a DBRef representation of an object. Polished DBRef creation implementation inside MappingMongoConverter. Removed collection and id attributes from @DBRef annotation as they have neither been documented nor used so far. Refactored MongoQueryCreator to be aware of the property and convert the given value into a DBRef if necessary.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011 by the original author(s).
+ * Copyright 2011-2012 by the original author(s).
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -265,6 +265,22 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 		return result;
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.convert.MongoWriter#toDBRef(java.lang.Object, org.springframework.data.mongodb.core.mapping.MongoPersistentProperty)
+	 */
+	public DBRef toDBRef(Object object, MongoPersistentProperty referingProperty) {
+
+		org.springframework.data.mongodb.core.mapping.DBRef annotation = null;
+
+		if (referingProperty != null) {
+			annotation = referingProperty.getDBRef();
+			Assert.isTrue(annotation != null, "The referenced property has to be mapped with @DBRef!");
+		}
+
+		return createDBRef(object, annotation);
+	}
+
 	/**
 	 * Root entry method into write conversion. Adds a type discriminator to the {@link DBObject}. Shouldn't be called for
 	 * nested conversions.
@@ -658,12 +674,20 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 
 	protected DBRef createDBRef(Object target, org.springframework.data.mongodb.core.mapping.DBRef dbref) {
 
+		Assert.notNull(target);
+
 		MongoPersistentEntity<?> targetEntity = mappingContext.getPersistentEntity(target.getClass());
-		if (null == targetEntity || null == targetEntity.getIdProperty()) {
-			return null;
+
+		if (null == targetEntity) {
+			throw new MappingException("No mapping metadata found for " + target.getClass());
 		}
 
 		MongoPersistentProperty idProperty = targetEntity.getIdProperty();
+
+		if (idProperty == null) {
+			throw new MappingException("No id property found on class " + targetEntity.getType());
+		}
+
 		BeanWrapper<MongoPersistentEntity<Object>, Object> wrapper = BeanWrapper.create(target, conversionService);
 		Object id = wrapper.getProperty(idProperty, Object.class, useFieldAccessOnly);
 
@@ -671,15 +695,10 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			throw new MappingException("Cannot create a reference to an object with a NULL id.");
 		}
 
-		String collection = dbref.collection();
-		if ("".equals(collection)) {
-			collection = targetEntity.getCollection();
-		}
+		DB db = mongoDbFactory.getDb();
+		db = dbref != null && StringUtils.hasText(dbref.db()) ? mongoDbFactory.getDb(dbref.db()) : db;
 
-		String dbname = dbref.db();
-		DB db = StringUtils.hasText(dbname) ? mongoDbFactory.getDb(dbname) : mongoDbFactory.getDb();
-
-		return new DBRef(db, collection, idMapper.convertId(id));
+		return new DBRef(db, targetEntity.getCollection(), idMapper.convertId(id));
 	}
 
 	protected Object getValueInternal(MongoPersistentProperty prop, DBObject dbo, SpELExpressionEvaluator eval,

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2011 the original author or authors.
+ * Copyright 2010-2012 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.
@@ -16,8 +16,10 @@
 package org.springframework.data.mongodb.core.convert;
 
 import org.springframework.data.convert.EntityWriter;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
 
 import com.mongodb.DBObject;
+import com.mongodb.DBRef;
 
 /**
  * A MongoWriter is responsible for converting an object of type T to the native MongoDB representation DBObject.
@@ -37,4 +39,14 @@ public interface MongoWriter<T> extends EntityWriter<T, DBObject> {
 	 * @return
 	 */
 	Object convertToMongoType(Object obj);
+
+	/**
+	 * Creates a {@link DBRef} to refer to the given object.
+	 * 
+	 * @param object the object to create a {@link DBRef} to link to. The object's type has to carry an id attribute.
+	 * @param referingProperty the client-side property referring to the object which might carry additional metadata for
+	 *          the {@link DBRef} object to create. Can be {@literal null}.
+	 * @return will never be {@literal null}.
+	 */
+	DBRef toDBRef(Object object, MongoPersistentProperty referingProperty);
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011 by the original author(s).
+ * Copyright 2011-2012 by the original author(s).
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,9 +13,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package org.springframework.data.mongodb.core.mapping;
 
+import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -24,19 +24,21 @@ import java.lang.annotation.Target;
 import org.springframework.data.annotation.Reference;
 
 /**
- * An annotation that indicates the annotated field is to be stored using a com.mongodb.DBRef
+ * An annotation that indicates the annotated field is to be stored using a {@link com.mongodb.DBRef}.
  * 
- * @author Jon Brisbin <jbrisbin@vmware.com>
+ * @author Jon Brisbin
+ * @authot Oliver Gierke
  */
+@Documented
 @Retention(RetentionPolicy.RUNTIME)
 @Target({ ElementType.FIELD })
 @Reference
 public @interface DBRef {
 
-	String collection() default "";
-
-	String id() default "";
-
+	/**
+	 * The database the referred entity resides in.
+	 * 
+	 * @return
+	 */
 	String db() default "";
-
 }

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

@@ -22,6 +22,7 @@ import org.springframework.data.domain.Sort;
 import org.springframework.data.mongodb.core.convert.MongoWriter;
 import org.springframework.data.mongodb.core.geo.Distance;
 import org.springframework.data.mongodb.core.geo.Point;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
 import org.springframework.data.repository.query.ParameterAccessor;
 import org.springframework.util.Assert;
 
@@ -137,37 +138,33 @@ public class ConvertingParameterAccessor implements MongoParameterAccessor {
 		}
 
 		/*
-		   * (non-Javadoc)
-		   *
-		   * @see java.util.Iterator#hasNext()
-		   */
+		 * (non-Javadoc)
+		 * @see java.util.Iterator#hasNext()
+		 */
 		public boolean hasNext() {
 			return delegate.hasNext();
 		}
 
 		/*
-		   * (non-Javadoc)
-		   *
-		   * @see java.util.Iterator#next()
-		   */
+		 * (non-Javadoc)
+		 * @see java.util.Iterator#next()
+		 */
 		public Object next() {
-
 			return delegate.next();
 		}
 
-		/* (non-Javadoc)
+		/* 
+		 * (non-Javadoc)
 		 * @see org.springframework.data.mongodb.repository.ConvertingParameterAccessor.PotentiallConvertingIterator#nextConverted()
 		 */
-		public Object nextConverted() {
-
-			return getConvertedValue(next());
+		public Object nextConverted(MongoPersistentProperty property) {
+			return property.isAssociation() ? writer.toDBRef(next(), property) : getConvertedValue(next());
 		}
 
 		/*
-		   * (non-Javadoc)
-		   *
-		   * @see java.util.Iterator#remove()
-		   */
+		 * (non-Javadoc)
+		 * @see java.util.Iterator#remove()
+		 */
 		public void remove() {
 			delegate.remove();
 		}
@@ -185,6 +182,6 @@ public class ConvertingParameterAccessor implements MongoParameterAccessor {
 		 * 
 		 * @return
 		 */
-		Object nextConverted();
+		Object nextConverted(MongoPersistentProperty property);
 	}
 }

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

@@ -98,7 +98,8 @@ class MongoQueryCreator extends AbstractQueryCreator<Query, Criteria> {
 		}
 
 		PersistentPropertyPath<MongoPersistentProperty> path = context.getPersistentPropertyPath(part.getProperty());
-		Criteria criteria = from(part.getType(),
+		MongoPersistentProperty property = path.getLeafProperty();
+		Criteria criteria = from(part.getType(), property,
 				where(path.toDotPath(MongoPersistentProperty.PropertyToFieldNameConverter.INSTANCE)),
 				(PotentiallyConvertingIterator) iterator);
 
@@ -116,10 +117,11 @@ class MongoQueryCreator extends AbstractQueryCreator<Query, Criteria> {
 			return create(part, iterator);
 		}
 
-		PersistentPropertyPath<MongoPersistentProperty> path2 = context.getPersistentPropertyPath(part.getProperty());
+		PersistentPropertyPath<MongoPersistentProperty> path = context.getPersistentPropertyPath(part.getProperty());
+		MongoPersistentProperty property = path.getLeafProperty();
 
-		Criteria criteria = from(part.getType(),
-				where(path2.toDotPath(MongoPersistentProperty.PropertyToFieldNameConverter.INSTANCE)),
+		Criteria criteria = from(part.getType(), property,
+				where(path.toDotPath(MongoPersistentProperty.PropertyToFieldNameConverter.INSTANCE)),
 				(PotentiallyConvertingIterator) iterator);
 
 		return criteria.andOperator(criteria);
@@ -164,34 +166,36 @@ class MongoQueryCreator extends AbstractQueryCreator<Query, Criteria> {
 	}
 
 	/**
-	 * Populates the given {@link CriteriaDefinition} depending on the {@link Type} given.
+	 * Populates the given {@link CriteriaDefinition} depending on the {@link Part} given.
 	 * 
-	 * @param type
+	 * @param part
+	 * @param property
 	 * @param criteria
 	 * @param parameters
 	 * @return
 	 */
-	private Criteria from(Type type, Criteria criteria, PotentiallyConvertingIterator parameters) {
+	private Criteria from(Type type, MongoPersistentProperty property, Criteria criteria,
+			PotentiallyConvertingIterator parameters) {
 
 		switch (type) {
 		case GREATER_THAN:
-			return criteria.gt(parameters.nextConverted());
+			return criteria.gt(parameters.nextConverted(property));
 		case GREATER_THAN_EQUAL:
-			return criteria.gte(parameters.nextConverted());
+			return criteria.gte(parameters.nextConverted(property));
 		case LESS_THAN:
-			return criteria.lt(parameters.nextConverted());
+			return criteria.lt(parameters.nextConverted(property));
 		case LESS_THAN_EQUAL:
-			return criteria.lte(parameters.nextConverted());
+			return criteria.lte(parameters.nextConverted(property));
 		case BETWEEN:
-			return criteria.gt(parameters.nextConverted()).lt(parameters.nextConverted());
+			return criteria.gt(parameters.nextConverted(property)).lt(parameters.nextConverted(property));
 		case IS_NOT_NULL:
 			return criteria.ne(null);
 		case IS_NULL:
 			return criteria.is(null);
 		case NOT_IN:
-			return criteria.nin(nextAsArray(parameters));
+			return criteria.nin(nextAsArray(parameters, property));
 		case IN:
-			return criteria.in(nextAsArray(parameters));
+			return criteria.in(nextAsArray(parameters, property));
 		case LIKE:
 			String value = parameters.next().toString();
 			return criteria.regex(toLikeRegex(value));
@@ -225,9 +229,9 @@ class MongoQueryCreator extends AbstractQueryCreator<Query, Criteria> {
 			Object parameter = parameters.next();
 			return criteria.within((Shape) parameter);
 		case SIMPLE_PROPERTY:
-			return criteria.is(parameters.nextConverted());
+			return criteria.is(parameters.nextConverted(property));
 		case NEGATING_SIMPLE_PROPERTY:
-			return criteria.not().is(parameters.nextConverted());
+			return criteria.not().is(parameters.nextConverted(property));
 		}
 
 		throw new IllegalArgumentException("Unsupported keyword!");
@@ -253,8 +257,8 @@ class MongoQueryCreator extends AbstractQueryCreator<Query, Criteria> {
 				parameter.getClass()));
 	}
 
-	private Object[] nextAsArray(PotentiallyConvertingIterator iterator) {
-		Object next = iterator.nextConverted();
+	private Object[] nextAsArray(PotentiallyConvertingIterator iterator, MongoPersistentProperty property) {
+		Object next = iterator.nextConverted(property);
 
 		if (next instanceof Collection) {
 			return ((Collection<?>) next).toArray();

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

@@ -37,6 +37,7 @@ import org.springframework.data.mongodb.core.query.NearQuery;
 
 import com.mongodb.BasicDBObject;
 import com.mongodb.DBObject;
+import com.mongodb.DBRef;
 
 /**
  * Abstract base class for unit tests to specify behaviour we expect from {@link MongoOperations}. Subclasses return
@@ -80,6 +81,10 @@ public abstract class MongoOperationsUnitTests {
 			public Object convertToMongoType(Object obj) {
 				return null;
 			}
+
+			public DBRef toDBRef(Object object, MongoPersistentProperty referingProperty) {
+				return null;
+			}
 		};
 	}
 

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

@@ -45,17 +45,20 @@ import org.springframework.beans.factory.annotation.Value;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.PersistenceConstructor;
+import org.springframework.data.mapping.PropertyPath;
 import org.springframework.data.mapping.model.MappingException;
 import org.springframework.data.mapping.model.MappingInstantiationException;
 import org.springframework.data.mongodb.MongoDbFactory;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
 import org.springframework.data.mongodb.core.mapping.PersonPojoStringId;
 import org.springframework.test.util.ReflectionTestUtils;
 
 import com.mongodb.BasicDBList;
 import com.mongodb.BasicDBObject;
 import com.mongodb.DBObject;
+import com.mongodb.DBRef;
 
 /**
  * Unit tests for {@link MappingMongoConverter}.
@@ -1031,6 +1034,37 @@ public class MappingMongoConverterUnitTests {
 		assertSyntheticFieldValueOf(outer.inner, outer);
 	}
 
+	/**
+	 * @see DATAMONGO-347
+	 */
+	@Test
+	public void createsSimpleDBRefCorrectly() {
+
+		Person person = new Person();
+		person.id = "foo";
+
+		DBRef dbRef = converter.toDBRef(person, null);
+		assertThat(dbRef.getId(), is((Object) "foo"));
+		assertThat(dbRef.getRef(), is("person"));
+	}
+
+	/**
+	 * @see DATAMONGO-347
+	 */
+	@Test
+	public void createsDBRefWithClientSpecCorrectly() {
+
+		PropertyPath path = PropertyPath.from("person", PersonClient.class);
+		MongoPersistentProperty property = mappingContext.getPersistentPropertyPath(path).getLeafProperty();
+
+		Person person = new Person();
+		person.id = "foo";
+
+		DBRef dbRef = converter.toDBRef(person, property);
+		assertThat(dbRef.getId(), is((Object) "foo"));
+		assertThat(dbRef.getRef(), is("person"));
+	}
+
 	private static void assertSyntheticFieldValueOf(Object target, Object expected) {
 
 		for (int i = 0; i < 10; i++) {
@@ -1081,6 +1115,10 @@ public class MappingMongoConverterUnitTests {
 	}
 
 	static class Person implements Contact {
+
+		@Id
+		String id;
+
 		LocalDate birthDate;
 
 		@Field("foo")
@@ -1185,6 +1223,12 @@ public class MappingMongoConverterUnitTests {
 		Inner inner;
 	}
 
+	static class PersonClient {
+
+		@org.springframework.data.mongodb.core.mapping.DBRef
+		Person person;
+	}
+
 	private class LocalDateToDateConverter implements Converter<LocalDate, Date> {
 
 		public Date convert(LocalDate source) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011 the original author or authors.
+ * Copyright 2011-2012 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.
@@ -32,6 +32,7 @@ import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Direction;
+import org.springframework.data.mongodb.core.MongoOperations;
 import org.springframework.data.mongodb.core.geo.Box;
 import org.springframework.data.mongodb.core.geo.Circle;
 import org.springframework.data.mongodb.core.geo.Distance;
@@ -53,6 +54,10 @@ public abstract class AbstractPersonRepositoryIntegrationTests {
 
 	@Autowired
 	protected PersonRepository repository;
+
+	@Autowired
+	MongoOperations operations;
+
 	Person dave, oliver, carter, boyd, stefan, leroi, alicia;
 	QPerson person;
 
@@ -404,4 +409,25 @@ public abstract class AbstractPersonRepositoryIntegrationTests {
 		assertThat(result.get(5), is(oliver));
 		assertThat(result.get(6), is(stefan));
 	}
+
+	/**
+	 * @see DATAMONGO-347
+	 */
+	@Test
+	public void executesQueryWithDBRefReferenceCorrectly() {
+
+		operations.remove(new org.springframework.data.mongodb.core.query.Query(), User.class);
+
+		User user = new User();
+		user.username = "Oliver";
+
+		operations.save(user);
+
+		dave.creator = user;
+		repository.save(dave);
+
+		List<Person> result = repository.findByCreator(user);
+		assertThat(result.size(), is(1));
+		assertThat(result, hasItem(dave));
+	}
 }

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

@@ -20,6 +20,7 @@ import java.util.Set;
 import org.springframework.data.mongodb.core.geo.Point;
 import org.springframework.data.mongodb.core.index.GeoSpatialIndexed;
 import org.springframework.data.mongodb.core.index.Indexed;
+import org.springframework.data.mongodb.core.mapping.DBRef;
 import org.springframework.data.mongodb.core.mapping.Document;
 
 /**
@@ -48,6 +49,9 @@ public class Person extends Contact {
 	private Address address;
 	private Set<Address> shippingAddresses;
 
+	@DBRef
+	User creator;
+
 	public Person() {
 
 		this(null, null);

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

@@ -151,4 +151,6 @@ public interface PersonRepository extends MongoRepository<Person, String>, Query
 	GeoResults<Person> findByLocationNear(Point point, Distance maxDistance);
 
 	GeoPage<Person> findByLocationNear(Point point, Distance maxDistance, Pageable pageable);
+
+	List<Person> findByCreator(User user);
 }

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

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2012 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.repository;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+@Document
+public class User {
+
+	@Id
+	String id;
+	String username;
+}

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

@@ -30,6 +30,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
+import org.mockito.Mockito;
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.mockito.stubbing.Answer;
@@ -39,6 +40,7 @@ import org.springframework.data.mongodb.core.convert.MongoConverter;
 import org.springframework.data.mongodb.core.geo.Distance;
 import org.springframework.data.mongodb.core.geo.Metrics;
 import org.springframework.data.mongodb.core.geo.Point;
+import org.springframework.data.mongodb.core.mapping.DBRef;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
@@ -212,7 +214,7 @@ public class MongoQueryCreatorUnitTests {
 	}
 
 	/**
-	 * @see DATAMONGO
+	 * @see DATAMONGO-413
 	 */
 	@Test
 	public void createsOrQueryCorrectly() {
@@ -225,6 +227,23 @@ public class MongoQueryCreatorUnitTests {
 				is(query(new Criteria().orOperator(where("firstName").is("Dave"), where("age").is(42))).getQueryObject()));
 	}
 
+	/**
+	 * @see DATAMONGO-347
+	 */
+	@Test
+	public void createsQueryReferencingADBRefCorrectly() {
+
+		User user = new User();
+		com.mongodb.DBRef dbref = new com.mongodb.DBRef(null, "user", "id");
+		when(converter.toDBRef(eq(user), Mockito.any(MongoPersistentProperty.class))).thenReturn(dbref);
+
+		PartTree tree = new PartTree("findByCreator", User.class);
+		MongoQueryCreator creator = new MongoQueryCreator(tree, getAccessor(converter, user), context);
+		Query query = creator.createQuery();
+
+		assertThat(query.getQueryObject(), is(query(where("creator").is(dbref)).getQueryObject()));
+	}
+
 	private void assertBindsDistanceToQuery(Point point, Distance distance, Query reference) throws Exception {
 
 		when(converter.convertToMongoType("Dave")).thenReturn("Dave");
@@ -252,5 +271,8 @@ public class MongoQueryCreatorUnitTests {
 
 		@Field("foo")
 		String username;
+
+		@DBRef
+		User creator;
 	}
 }