From 278e51c3cd5f990eeea3fa8769b4eb0512ab06a3 Mon Sep 17 00:00:00 2001
From: Takuya Kitazawa <k.takuti@gmail.com>
Date: Tue, 10 Apr 2018 13:57:02 +0900
Subject: [PATCH] Avoid KryoException: java.lang.NullPointerException

---
 nlp/src/main/java/hivemall/nlp/tokenizer/KuromojiUDF.java | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/nlp/src/main/java/hivemall/nlp/tokenizer/KuromojiUDF.java b/nlp/src/main/java/hivemall/nlp/tokenizer/KuromojiUDF.java
index 411c89e16..384c317a5 100644
--- a/nlp/src/main/java/hivemall/nlp/tokenizer/KuromojiUDF.java
+++ b/nlp/src/main/java/hivemall/nlp/tokenizer/KuromojiUDF.java
@@ -69,7 +69,10 @@ public final class KuromojiUDF extends GenericUDF {
     private static final long MAX_INPUT_STREAM_SIZE = 32L * 1024L * 1024L; // ~32MB
 
     private Mode _mode;
-    private CharArraySet _stopWords;
+
+    // lazy instantiation to avoid org.apache.hive.com.esotericsoftware.kryo.KryoException: java.lang.NullPointerException
+    private transient CharArraySet _stopWords;
+
     private Set<String> _stopTags;
     private UserDictionary _userDict;