From a8a469fa06f0a61034982a9f10458621716e7250 Mon Sep 17 00:00:00 2001
From: Jeff Zhang <zjffdu@apache.org>
Date: Thu, 27 Sep 2018 11:29:43 +0800
Subject: [PATCH] ZEPPELIN-3794. NPE when running paragraph without interpreter
 specified

---
 .../src/main/java/org/apache/zeppelin/notebook/Note.java      | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/zeppelin-zengine/src/main/java/org/apache/zeppelin/notebook/Note.java b/zeppelin-zengine/src/main/java/org/apache/zeppelin/notebook/Note.java
index 8f916e1a6cd..74b08b25ca8 100644
--- a/zeppelin-zengine/src/main/java/org/apache/zeppelin/notebook/Note.java
+++ b/zeppelin-zengine/src/main/java/org/apache/zeppelin/notebook/Note.java
@@ -195,6 +195,10 @@ public void setPath(String path) {
   }
 
   public String getDefaultInterpreterGroup() {
+    if (defaultInterpreterGroup == null) {
+      defaultInterpreterGroup = ZeppelinConfiguration.create()
+          .getString(ZeppelinConfiguration.ConfVars.ZEPPELIN_INTERPRETER_GROUP_DEFAULT);
+    }
     return defaultInterpreterGroup;
   }