DATAMONGO-1207 - Fixed potential NPE in MongoTemplate.doInsertAll(…).

If a collection containing null values is handed to MongoTempalte.insertAll(…), a NullPointerException was caused by the unguarded attempt to lookup the class of the element. We now explicitly handle this case and skip the element.

Some code cleanups in MongoTemplate.doInsertAll(…).

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

@@ -767,27 +767,33 @@ public class MongoTemplate implements MongoOperations, ApplicationContextAware {
 	}
 
 	protected <T> void doInsertAll(Collection<? extends T> listToSave, MongoWriter<T> writer) {
-		Map<String, List<T>> objs = new HashMap<String, List<T>>();
 
-		for (T o : listToSave) {
+		Map<String, List<T>> elementsByCollection = new HashMap<String, List<T>>();
+
+		for (T element : listToSave) {
+
+			if (element == null) {
+				continue;
+			}
+
+			MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(element.getClass());
 
-			MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(o.getClass());
 			if (entity == null) {
-				throw new InvalidDataAccessApiUsageException("No Persitent Entity information found for the class "
-						+ o.getClass().getName());
+				throw new InvalidDataAccessApiUsageException("No PersistentEntity information found for " + element.getClass());
 			}
+
 			String collection = entity.getCollection();
+			List<T> collectionElements = elementsByCollection.get(collection);
 
-			List<T> objList = objs.get(collection);
-			if (null == objList) {
-				objList = new ArrayList<T>();
-				objs.put(collection, objList);
+			if (null == collectionElements) {
+				collectionElements = new ArrayList<T>();
+				elementsByCollection.put(collection, collectionElements);
 			}
-			objList.add(o);
 
+			collectionElements.add(element);
 		}
 
-		for (Map.Entry<String, List<T>> entry : objs.entrySet()) {
+		for (Map.Entry<String, List<T>> entry : elementsByCollection.entrySet()) {
 			doInsertBatch(entry.getKey(), entry.getValue(), this.mongoConverter);
 		}
 	}

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

@@ -74,6 +74,7 @@ import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.Update;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
 import com.mongodb.BasicDBObject;
@@ -188,6 +189,7 @@ public class MongoTemplateTests {
 		template.dropCollection(DocumentWithDBRefCollection.class);
 		template.dropCollection(SomeContent.class);
 		template.dropCollection(SomeTemplate.class);
+		template.dropCollection(Address.class);
 	}
 
 	@Test
@@ -2740,6 +2742,23 @@ public class MongoTemplateTests {
 		assertThat(template.findAll(DBObject.class, "collection"), hasSize(0));
 	}
 
+	/**
+	 * @see DATAMONGO-1207
+	 */
+	@Test
+	public void ignoresNullElementsForInsertAll() {
+
+		Address newYork = new Address("NY", "New York");
+		Address washington = new Address("DC", "Washington");
+
+		template.insertAll(Arrays.asList(newYork, null, washington));
+
+		List<Address> result = template.findAll(Address.class);
+
+		assertThat(result, hasSize(2));
+		assertThat(result, hasItems(newYork, washington));
+	}
+
 	static class DoucmentWithNamedIdField {
 
 		@Id String someIdKey;
@@ -2926,6 +2945,41 @@ public class MongoTemplateTests {
 
 		String state;
 		String city;
+
+		Address() {}
+
+		Address(String state, String city) {
+			this.state = state;
+			this.city = city;
+		}
+
+		@Override
+		public boolean equals(Object obj) {
+
+			if (obj == this) {
+				return true;
+			}
+
+			if (!(obj instanceof Address)) {
+				return false;
+			}
+
+			Address that = (Address) obj;
+
+			return ObjectUtils.nullSafeEquals(this.city, that.city) && //
+					ObjectUtils.nullSafeEquals(this.state, that.state);
+		}
+
+		@Override
+		public int hashCode() {
+
+			int result = 17;
+
+			result += 31 * ObjectUtils.nullSafeHashCode(this.city);
+			result += 31 * ObjectUtils.nullSafeHashCode(this.state);
+
+			return result;
+		}
 	}
 
 	static class VersionedPerson {