Added field attribute to @Query annotation.

The fields attribute allows specifying which fields of matching documents should be unmarshalled.

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/MongoQueryMethod.java

@@ -83,6 +83,18 @@ class MongoQueryMethod extends QueryMethod {
 		String query = (String) AnnotationUtils.getValue(getQueryAnnotation());
 		return StringUtils.hasText(query) ? query : null;
 	}
+	
+	/**
+	 * Returns the field specification to be used for the query.
+	 * 
+	 * @return
+	 */
+	String getFieldSpecification() {
+		
+		String value = (String) AnnotationUtils.getValue(getQueryAnnotation(), "fields");
+		return StringUtils.hasText(value) ? value : null;
+	}
+	
 
 	/**
 	 * Returns the {@link Query} annotation that is applied to the method or {@code null} if none available.

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/Query.java

@@ -33,4 +33,6 @@ import java.lang.annotation.Target;
 public @interface Query {
 
     String value() default "";
+    
+    String fields() default "";
 }