Ok, thanks for additional information. So maybe the issue is somehow related to JVM environment. 
I noticed that you're setting following property: System.setProperty("file.encoding", "UTF-8");
Java sets file.encoding once at JVM startup — setting it with System.setProperty at runtime has no effect on string decoding in most libraries, including JDBC drivers.

Try to launch your application with following  VM option. 

java -Dfile.encoding=UTF-8