From 1bc028c7a3507bdfa73d04344b8822c6ae2a62cd Mon Sep 17 00:00:00 2001
From: David Berdik <berdikd@duq.edu>
Date: Sun, 14 Apr 2019 17:55:07 -0400
Subject: [PATCH] Fixed occasional "NullPointerException" occurring when using
 the experiment engine

---
 src/com/jgaap/backend/ExperimentEngine.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/com/jgaap/backend/ExperimentEngine.java b/src/com/jgaap/backend/ExperimentEngine.java
index 615256911..3f6046a86 100644
--- a/src/com/jgaap/backend/ExperimentEngine.java
+++ b/src/com/jgaap/backend/ExperimentEngine.java
@@ -253,7 +253,7 @@ public String call() throws Exception {
 				Path filePath = FileSystems.getDefault().getPath(fileName);
 				Writer writer = Files.newBufferedWriter(filePath, Charset.defaultCharset(), StandardOpenOption.CREATE);
 				for (Document resultDocument : resultDocuments) {
-					if (!resultDocument.getFormattedResult(analysisDriver).equals("null"))
+					if (resultDocument.getFormattedResult(analysisDriver) != null && !resultDocument.getFormattedResult(analysisDriver).equals("null"))
 						writer.append(resultDocument.getFormattedResult(analysisDriver));
 				}
 				writer.close();