DATAMONGO-1325 - Polishing.

Add since tag to new method. Set year of inception in copyright header. Add ticket reference to test. Minor code reformatting. Add integration test.

Change query keyword for query-by-example from $sample to $example to prevent accidental collisions.

Remove Mongo 3.4-next build profile due to removed Mongo 3.4 driver snapshots.

Original pull request: spring-projects#452.

Author: mp911de

.travis.yml

@@ -9,7 +9,6 @@ before_script:
 env:
   matrix:
     - PROFILE=ci
-    - PROFILE=mongo34-next
     - PROFILE=mongo35-next
 
 # Current MongoDB version is 2.4.2 as of 2016-04, see https://github.com/travis-ci/travis-ci/issues/3694

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

@@ -17,23 +17,17 @@
 
 import static org.springframework.data.mongodb.core.aggregation.Fields.*;
 
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
 import org.bson.Document;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Direction;
 import org.springframework.data.mongodb.core.aggregation.CountOperation.CountOperationBuilder;
-import org.springframework.data.mongodb.core.aggregation.ExposedFields.DirectFieldReference;
-import org.springframework.data.mongodb.core.aggregation.ExposedFields.ExposedField;
-import org.springframework.data.mongodb.core.aggregation.ExposedFields.FieldReference;
 import org.springframework.data.mongodb.core.aggregation.FacetOperation.FacetOperationBuilder;
-import org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation;
 import org.springframework.data.mongodb.core.aggregation.GraphLookupOperation.StartWithBuilder;
 import org.springframework.data.mongodb.core.aggregation.ReplaceRootOperation.ReplaceRootDocumentOperationBuilder;
 import org.springframework.data.mongodb.core.aggregation.ReplaceRootOperation.ReplaceRootOperationBuilder;
-import org.springframework.data.mongodb.core.aggregation.Fields.*;
 import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.CriteriaDefinition;
 import org.springframework.data.mongodb.core.query.NearQuery;
@@ -384,15 +378,16 @@ public static LimitOperation limit(long maxElements) {
 	}
 
 	/**
-	 * Creates a new {@link SampleOperation} to selects the specified number of documents from its input randomly.
+	 * Creates a new {@link SampleOperation} to select the specified number of documents from its input randomly.
 	 *
 	 * @param sampleSize must not be less than zero.
 	 * @return
+	 * @since 2.0
 	 */
 	public static SampleOperation sample(long sampleSize) {
 		return new SampleOperation(sampleSize);
 	}
-	
+
 	/**
 	 * Creates a new {@link MatchOperation} using the given {@link Criteria}.
 	 *

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2017 the original author or authors.
+ * Copyright 2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,7 +26,8 @@
  *
  * @author Gustavo de Geus
  * @since 2.0
- * @see <a href="https://docs.mongodb.com/master/reference/operator/aggregation/sample/">MongoDB Aggregation Framework: $sample</a>
+ * @see <a href="https://docs.mongodb.com/master/reference/operator/aggregation/sample/">MongoDB Aggregation Framework:
+ *      $sample</a>
  */
 public class SampleOperation implements AggregationOperation {