add Java test case

Author: Jacky Li

mllib/src/test/java/org/apache/spark/mllib/fpm/JavaFPGrowthSuite.java

@@ -0,0 +1,96 @@
+/*
+ * 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.mllib.fpm;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+import com.google.common.collect.Lists;
+
+import org.apache.spark.api.java.JavaRDD;
+import org.apache.spark.api.java.JavaSparkContext;
+
+public class JavaFPGrowthSuite implements Serializable {
+    private transient JavaSparkContext sc;
+
+    @Before
+    public void setUp() {
+        sc = new JavaSparkContext("local", "JavaFPGrowth");
+    }
+
+    @After
+    public void tearDown() {
+        sc.stop();
+        sc = null;
+    }
+
+    @Test
+    public void runFPGrowth() {
+        JavaRDD<ArrayList<String>> rdd = sc.parallelize(Lists.newArrayList(
+                Lists.newArrayList("r z h k p".split(" ")),
+                Lists.newArrayList("z y x w v u t s".split(" ")),
+                Lists.newArrayList("s x o n r".split(" ")),
+                Lists.newArrayList("x z y m t s q e".split(" ")),
+                Lists.newArrayList("z".split(" ")),
+                Lists.newArrayList("x z y r q t p".split(" "))), 2);
+
+        FPGrowth fpg = new FPGrowth();
+
+        /*
+        FPGrowthModel model6 = fpg
+                .setMinSupport(0.9)
+                .setNumPartitions(1)
+                .run(rdd);
+        assert(model6.javaFreqItemsets().count() == 0);
+
+        FPGrowthModel model3 = fpg
+                .setMinSupport(0.5)
+                .setNumPartitions(2)
+                .run(rdd);
+        val freqItemsets3 = model3.freqItemsets.collect().map { case (items, count) =>
+            (items.toSet, count)
+        }
+        val expected = Set(
+                (Set("s"), 3L), (Set("z"), 5L), (Set("x"), 4L), (Set("t"), 3L), (Set("y"), 3L),
+        (Set("r"), 3L),
+        (Set("x", "z"), 3L), (Set("t", "y"), 3L), (Set("t", "x"), 3L), (Set("s", "x"), 3L),
+        (Set("y", "x"), 3L), (Set("y", "z"), 3L), (Set("t", "z"), 3L),
+        (Set("y", "x", "z"), 3L), (Set("t", "x", "z"), 3L), (Set("t", "y", "z"), 3L),
+        (Set("t", "y", "x"), 3L),
+        (Set("t", "y", "x", "z"), 3L))
+        assert(freqItemsets3.toSet === expected)
+
+        val model2 = fpg
+                .setMinSupport(0.3)
+                .setNumPartitions(4)
+                .run[String](rdd)
+        assert(model2.freqItemsets.count() == 54)
+
+        val model1 = fpg
+                .setMinSupport(0.1)
+                .setNumPartitions(8)
+                .run[String](rdd)
+        assert(model1.freqItemsets.count() == 625) */
+    }
+}