DATAMONGO-1431 - Added MongoOperations.stream(…) with explicit collection.

Author: odrotbohm

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

@@ -175,13 +175,28 @@ public interface MongoOperations {
 	 * Returns a {@link CloseableIterator} that wraps the a Mongo DB {@link Cursor} that needs to be closed.
 	 * 
 	 * @param <T> element return type
-	 * @param query
-	 * @param entityType
-	 * @return
+	 * @param query must not be {@literal null}.
+	 * @param entityType must not be {@literal null}.
+	 * @return will never be {@literal null}.
 	 * @since 1.7
 	 */
 	<T> CloseableIterator<T> stream(Query query, Class<T> entityType);
 
+	/**
+	 * Executes the given {@link Query} on the entity collection of the specified {@code entityType} and collection backed
+	 * by a Mongo DB {@link Cursor}.
+	 * <p>
+	 * Returns a {@link CloseableIterator} that wraps the a Mongo DB {@link Cursor} that needs to be closed.
+	 * 
+	 * @param <T> element return type
+	 * @param query must not be {@literal null}.
+	 * @param entityType must not be {@literal null}.
+	 * @param collectionName must not be {@literal null} or empty.
+	 * @return will never be {@literal null}.
+	 * @since 1.10
+	 */
+	<T> CloseableIterator<T> stream(Query query, Class<T> entityType, String collectionName);
+
 	/**
 	 * Create an uncapped collection with a name based on the provided entity class.
 	 * 
@@ -1031,5 +1046,4 @@ <T> T findAndModify(Query query, Update update, FindAndModifyOptions options, Cl
 	 * @return
 	 */
 	MongoConverter getConverter();
-
 }

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

@@ -326,7 +326,21 @@ public MongoConverter getConverter() {
 	@Override
 	public <T> CloseableIterator<T> stream(final Query query, final Class<T> entityType) {
 
-		return execute(entityType, new CollectionCallback<CloseableIterator<T>>() {
+		return stream(query, entityType, determineCollectionName(entityType));
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.MongoOperations#stream(org.springframework.data.mongodb.core.query.Query, java.lang.Class, java.lang.String)
+	 */
+	@Override
+	public <T> CloseableIterator<T> stream(final Query query, final Class<T> entityType, String collectionName) {
+
+		Assert.notNull(query, "Query must not be null!");
+		Assert.notNull(entityType, "Entity type must not be null!");
+		Assert.hasText(collectionName, "Collection name must not be null or empty!");
+
+		return execute(collectionName, new CollectionCallback<CloseableIterator<T>>() {
 
 			@Override
 			public CloseableIterator<T> doInCollection(DBCollection collection) throws MongoException, DataAccessException {

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

@@ -3344,6 +3344,30 @@ public void updatesBigNumberValueUsingStringComparisonWhenUsingMinOperator() {
 		assertThat(loaded.bigDeciamVal, equalTo(new BigDecimal("800")));
 	}
 
+	/**
+	 * @see DATAMONGO-1431
+	 */
+	@Test
+	public void streamExecutionUsesExplicitCollectionName() {
+
+		template.remove(new Query(), "some_special_collection");
+		template.remove(new Query(), Document.class);
+
+		Document document = new Document();
+
+		template.insert(document, "some_special_collection");
+
+		CloseableIterator<Document> stream = template.stream(new Query(), Document.class);
+
+		assertThat(stream.hasNext(), is(false));
+
+		stream = template.stream(new Query(), Document.class, "some_special_collection");
+
+		assertThat(stream.hasNext(), is(true));
+		assertThat(stream.next().id, is(document.id));
+		assertThat(stream.hasNext(), is(false));
+	}
+
 	static class TypeWithNumbers {
 
 		@Id String id;