[SPARK-10626] [MLLIB] create java friendly method for random rdd

SPARK-3136 added a large number of functions for creating Java RandomRDDs, but for people that want to use custom RandomDataGenerators we should make a Java friendly method.

Author: Holden Karau <holden@pigscanfly.ca>

Closes #8782 from holdenk/SPARK-10626-create-java-friendly-method-for-randomRDD.

1 files changed, 30 insertions, 0 deletions

diff --git a/mllib/src/test/java/org/apache/spark/mllib/random/JavaRandomRDDsSuite.java b/mllib/src/test/java/org/apache/spark/mllib/random/JavaRandomRDDsSuite.java
index 33d81b1e95..fce5f6712f 100644
--- a/mllib/src/test/java/org/apache/spark/mllib/random/JavaRandomRDDsSuite.java
+++ b/mllib/src/test/java/org/apache/spark/mllib/random/JavaRandomRDDsSuite.java
@@ -17,6 +17,7 @@
 
 package org.apache.spark.mllib.random;
 
+import java.io.Serializable;
 import java.util.Arrays;
 
 import org.apache.spark.api.java.JavaRDD;
@@ -231,4 +232,33 @@ public class JavaRandomRDDsSuite {
     }
   }
 
+  @Test
+  public void testArbitrary() {
+    long size = 10;
+    long seed = 1L;
+    int numPartitions = 0;
+    StringGenerator gen = new StringGenerator();
+    JavaRDD<String> rdd1 = randomJavaRDD(sc, gen, size);
+    JavaRDD<String> rdd2 = randomJavaRDD(sc, gen, size, numPartitions);
+    JavaRDD<String> rdd3 = randomJavaRDD(sc, gen, size, numPartitions, seed);
+    for (JavaRDD<String> rdd: Arrays.asList(rdd1, rdd2, rdd3)) {
+      Assert.assertEquals(size, rdd.count());
+      Assert.assertEquals(2, rdd.first().length());
+    }
+  }
+}
+
+// This is just a test generator, it always returns a string of 42
+class StringGenerator implements RandomDataGenerator<String>, Serializable {
+  @Override
+  public String nextValue() {
+    return "42";
+  }
+  @Override
+  public StringGenerator copy() {
+    return new StringGenerator();
+  }
+  @Override
+  public void setSeed(long seed) {
+  }
 }