Changed to oraclejdk9 to see if it works fine.

jgebal · jgebal · commit fc3a17f6380f · 2019-06-21T01:59:28.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -2,7 +2,7 @@ sudo: required
 
 language: java
 jdk:
-  - oraclejdk8
+  - oraclejdk9
 
 addons:
   sonarcloud:
