add Java unit test for VectorAssembler

mllib/src/test/java/org/apache/spark/ml/feature/JavaVectorAssemblerSuite.java

@@ -0,0 +1,77 @@
+/*
+ * 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.feature;
+
+import java.util.Arrays;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.apache.spark.api.java.JavaRDD;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.mllib.linalg.Vector;
+import org.apache.spark.mllib.linalg.VectorUDT;
+import org.apache.spark.mllib.linalg.Vectors;
+import org.apache.spark.sql.DataFrame;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.RowFactory;
+import org.apache.spark.sql.SQLContext;
+import org.apache.spark.sql.types.*;
+
+public class JavaVectorAssemblerSuite {
+  private transient JavaSparkContext jsc;
+  private transient SQLContext sqlContext;
+
+  @Before
+  public void setUp() {
+    jsc = new JavaSparkContext("local", "JavaVectorAssemblerSuite");
+    sqlContext = new SQLContext(jsc);
+  }
+
+  @After
+  public void tearDown() {
+    jsc.stop();
+    jsc = null;
+  }
+
+  @Test
+  public void testVectorAssembler() {
+    StructType schema = new StructType(new StructField[] {
+      new StructField("id", IntegerType$.MODULE$, false, Metadata.empty()),
+      new StructField("x", DoubleType$.MODULE$, false, Metadata.empty()),
+      new StructField("y", new VectorUDT(), false, Metadata.empty()),
+      new StructField("name", StringType$.MODULE$, false, Metadata.empty()),
+      new StructField("z", new VectorUDT(), false, Metadata.empty()),
+      new StructField("n", LongType$.MODULE$, false, Metadata.empty())
+    });
+    Row row = RowFactory.create(
+      0, 0.0, Vectors.dense(1.0, 2.0), "a",
+      Vectors.sparse(2, new int[] {1}, new double[] {3.0}), 10L);
+    JavaRDD<Row> rdd = jsc.parallelize(Arrays.asList(row));
+    DataFrame dataset = sqlContext.createDataFrame(rdd, schema);
+    VectorAssembler assembler = new VectorAssembler()
+      .setInputCols(new String[] {"x", "y", "z", "n"})
+      .setOutputCol("features");
+    DataFrame output = assembler.transform(dataset);
+    Assert.assertEquals(
+      Vectors.sparse(6, new int[] {1, 2, 4, 5}, new double[] {1.0, 2.0, 3.0, 10.0}),
+      output.first().<Vector>getAs(0));
+  }
+}