DATAMONGO-471 - Add support for $each when using $addToSet.

Additionally to Update.addToSet(String, Object) the method 'addToSet(String)' has been introduced, returning a builder to allow the creation of $addToSet command for either single value, or multiple values using $each.

Using value:
new Update().addToSet("key").value("spring");

Using each:
new Update().addToSet("key").each("spring", "data", "mongodb");

Original Pull Request: #157.

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

@@ -196,6 +196,18 @@ public class Update {
 		return this;
 	}
 
+	/**
+	 * Update using {@code $addToSet} modifier. <br/>
+	 * Allows creation of {@code $push} command for single or multiple (using {@code $each}) values
+	 * 
+	 * @param key
+	 * @return
+	 * @since 1.5
+	 */
+	public AddToSetBuilder addToSet(String key) {
+		return new AddToSetBuilder(key);
+	}
+
 	/**
 	 * Update using the {@literal $addToSet} update modifier
 	 * 
@@ -408,7 +420,7 @@ public class Update {
 	/**
 	 * Builder for creating {@code $push} modifiers
 	 * 
-	 * @author Christop Strobl
+	 * @author Christoph Strobl
 	 */
 	public class PushOperatorBuilder {
 
@@ -442,4 +454,41 @@ public class Update {
 			return Update.this.push(key, value);
 		}
 	}
+
+	/**
+	 * Builder for creating {@code $addToSet} modifier.
+	 * 
+	 * @author Christoph Strobl
+	 * @since 1.5
+	 */
+	public class AddToSetBuilder {
+
+		private final String key;
+
+		public AddToSetBuilder(String key) {
+			this.key = key;
+		}
+
+		/**
+		 * Propagates {@code $each} to {@code $addToSet}
+		 * 
+		 * @param values
+		 * @return
+		 */
+		public Update each(Object... values) {
+			return Update.this.addToSet(this.key, new Each(values));
+		}
+
+		/**
+		 * Propagates {@link #value(Object)} to {@code $addToSet}
+		 * 
+		 * @param values
+		 * @return
+		 */
+		public Update value(Object value) {
+			return Update.this.addToSet(this.key, value);
+		}
+
+	}
+
 }

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

@@ -2580,6 +2580,25 @@ public class MongoTemplateTests {
 		assertThat(savedTmpl.getContent().getText(), is(nullValue()));
 	}
 
+	/**
+	 * @see DATAMONGO-471
+	 */
+	@Test
+	public void updateMultiShouldAddValuesCorrectlyWhenUsingAddToSetWithEach() {
+
+		DocumentWithCollectionOfSimpleType document = new DocumentWithCollectionOfSimpleType();
+		document.values = Arrays.asList("spring");
+		template.save(document);
+
+		Query query = query(where("id").is(document.id));
+		assumeThat(template.findOne(query, DocumentWithCollectionOfSimpleType.class).values, hasSize(1));
+
+		Update update = new Update().addToSet("values").each("data", "mongodb");
+		template.updateMulti(query, update, DocumentWithCollectionOfSimpleType.class);
+
+		assertThat(template.findOne(query, DocumentWithCollectionOfSimpleType.class).values, hasSize(3));
+	}
+
 	static class DocumentWithDBRefCollection {
 
 		@Id public String id;

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

@@ -412,6 +412,46 @@ public class UpdateMapperUnitTests {
 		assertThat(inClause, IsIterableContainingInOrder.<Object> contains(1L, 2L));
 	}
 
+	/**
+	 * @see DATAMONG0-471
+	 */
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	@Test
+	public void testUpdateShouldApply$addToSetCorrectlyWhenUsedWith$each() {
+
+		Update update = new Update().addToSet("values").each("spring", "data", "mongodb");
+		DBObject mappedObject = mapper.getMappedObject(update.getUpdateObject(),
+				context.getPersistentEntity(ListModel.class));
+
+		DBObject addToSet = getAsDBObject(mappedObject, "$addToSet");
+		DBObject values = getAsDBObject(addToSet, "values");
+		BasicDBList each = getAsDBList(values, "$each");
+
+		assertThat(each.toMap(), (Matcher) allOf(hasValue("spring"), hasValue("data"), hasValue("mongodb")));
+	}
+
+	/**
+	 * @see DATAMONG0-471
+	 */
+	@Test
+	public void testUpdateShouldRetainClassTypeInformationWhenUsing$addToSetWith$eachForCustomTypes() {
+
+		Update update = new Update().addToSet("models").each(new ModelImpl(2014), new ModelImpl(1), new ModelImpl(28));
+		DBObject mappedObject = mapper.getMappedObject(update.getUpdateObject(),
+				context.getPersistentEntity(ModelWrapper.class));
+
+		DBObject addToSet = getAsDBObject(mappedObject, "$addToSet");
+
+		DBObject values = getAsDBObject(addToSet, "models");
+		BasicDBList each = getAsDBList(values, "$each");
+
+		for (Object updateValue : each) {
+			assertThat(((DBObject) updateValue).get("_class").toString(),
+					equalTo("org.springframework.data.mongodb.core.convert.UpdateMapperUnitTests$ModelImpl"));
+		}
+
+	}
+
 	static interface Model {}
 
 	static class ModelImpl implements Model {
@@ -425,6 +465,12 @@ public class UpdateMapperUnitTests {
 
 	public class ModelWrapper {
 		Model model;
+
+		public ModelWrapper() {}
+
+		public ModelWrapper(Model model) {
+			this.model = model;
+		}
 	}
 
 	static class ListModelWrapper {