content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.spark.ml.clustering;
  
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.List;
  
  import org.junit.Test;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  
  import org.apache.spark.SharedSparkSession;
  import org.apache.spark.ml.linalg.Vector;
  import org.apache.spark.sql.Dataset;
  import org.apache.spark.sql.Row;
  
  public class JavaKMeansSuite extends SharedSparkSession {
  
    private transient int k = 5;
    private transient Dataset<Row> dataset;
  
    @Override
    public void setUp() throws IOException {
      super.setUp();
      dataset = KMeansSuite.generateKMeansData(spark, 50, 3, k);
    }
  
    @Test
    public void fitAndTransform() {
      KMeans kmeans = new KMeans().setK(k).setSeed(1);
      KMeansModel model = kmeans.fit(dataset);
  
      Vector[] centers = model.clusterCenters();
      assertEquals(k, centers.length);
  
      Dataset<Row> transformed = model.transform(dataset);
      List<String> columns = Arrays.asList(transformed.columns());
      List<String> expectedColumns = Arrays.asList("features", "prediction");
      for (String column : expectedColumns) {
        assertTrue(columns.contains(column));
      }
    }
  }
  