DATAMONGO-944 - Add support for $currentDate to Update.

Added currentDate and currentTimestamp to Update.

Original pull request: #200.

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

@@ -280,6 +280,34 @@ public class Update {
 		return this;
 	}
 
+	/**
+	 * Update given key to current date using {@literal $currentDate} modifier.
+	 * 
+	 * @see http://docs.mongodb.org/manual/reference/operator/update/currentDate/
+	 * @param key
+	 * @return
+	 * @since 1.6
+	 */
+	public Update currentDate(String key) {
+
+		addMultiFieldOperation("$currentDate", key, true);
+		return this;
+	}
+
+	/**
+	 * Update given key to current date using {@literal $currentDate : { $type : "timestamp" }} modifier.
+	 * 
+	 * @see http://docs.mongodb.org/manual/reference/operator/update/currentDate/
+	 * @param key
+	 * @return
+	 * @since 1.6
+	 */
+	public Update currentTimestamp(String key) {
+
+		addMultiFieldOperation("$currentDate", key, new BasicDBObject("$type", "timestamp"));
+		return this;
+	}
+
 	public DBObject getUpdateObject() {
 
 		DBObject dbo = new BasicDBObject();

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

@@ -23,6 +23,9 @@ import java.util.Map;
 
 import org.junit.Test;
 
+import com.mongodb.BasicDBObject;
+import com.mongodb.BasicDBObjectBuilder;
+
 /**
  * Test cases for {@link Update}.
  * 
@@ -342,4 +345,68 @@ public class UpdateTests {
 				+ "\"$push\" : { \"authors\" : { \"name\" : \"Sven\"}} " //
 				+ ", \"$pop\" : { \"authors\" : -1}}")); //
 	}
+
+	/**
+	 * @see DATAMONGO-944
+	 */
+	@Test
+	public void getUpdateObjectShouldReturnCurrentDateCorrectlyForSingleFieldWhenUsingDate() {
+
+		Update update = new Update().currentDate("foo");
+		assertThat(update.getUpdateObject(),
+				equalTo(new BasicDBObjectBuilder().add("$currentDate", new BasicDBObject("foo", true)).get()));
+	}
+
+	/**
+	 * @see DATAMONGO-944
+	 */
+	@Test
+	public void getUpdateObjectShouldReturnCurrentDateCorrectlyForMultipleFieldsWhenUsingDate() {
+
+		Update update = new Update().currentDate("foo").currentDate("bar");
+		assertThat(update.getUpdateObject(),
+				equalTo(new BasicDBObjectBuilder().add("$currentDate", new BasicDBObject("foo", true).append("bar", true))
+						.get()));
+	}
+
+	/**
+	 * @see DATAMONGO-944
+	 */
+	@Test
+	public void getUpdateObjectShouldReturnCurrentDateCorrectlyForSingleFieldWhenUsingTimestamp() {
+
+		Update update = new Update().currentTimestamp("foo");
+		assertThat(
+				update.getUpdateObject(),
+				equalTo(new BasicDBObjectBuilder().add("$currentDate",
+						new BasicDBObject("foo", new BasicDBObject("$type", "timestamp"))).get()));
+	}
+
+	/**
+	 * @see DATAMONGO-944
+	 */
+	@Test
+	public void getUpdateObjectShouldReturnCurrentDateCorrectlyForMultipleFieldsWhenUsingTimestamp() {
+
+		Update update = new Update().currentTimestamp("foo").currentTimestamp("bar");
+		assertThat(
+				update.getUpdateObject(),
+				equalTo(new BasicDBObjectBuilder().add(
+						"$currentDate",
+						new BasicDBObject("foo", new BasicDBObject("$type", "timestamp")).append("bar", new BasicDBObject("$type",
+								"timestamp"))).get()));
+	}
+
+	/**
+	 * @see DATAMONGO-944
+	 */
+	@Test
+	public void getUpdateObjectShouldReturnCurrentDateCorrectlyWhenUsingMixedDateAndTimestamp() {
+
+		Update update = new Update().currentDate("foo").currentTimestamp("bar");
+		assertThat(
+				update.getUpdateObject(),
+				equalTo(new BasicDBObjectBuilder().add("$currentDate",
+						new BasicDBObject("foo", true).append("bar", new BasicDBObject("$type", "timestamp"))).get()));
+	}
 }