Install Java devilment toolkit 1.8 (required, higher version Java may not work properly with Spark, we found out jdk1.8.0_191 works well, therefore, recommend jdk1.8.0_191. (Do NOT install JDK 9 or above, Spark is not currently compatible with JDK 9 or above.)
JDK Windows (10) installation.
No blank space allowed in JDK folder name
Avoid install Java Development Kit into a folder which name contains space, such as c:\program files or c:\program files (x86). Best should be no space in folder name. If you installed JDK under c\:program files or c\:program files (x86), you will need to later in your Scala code set environment variable JAVA_HOME to
If JDK is in C:\Program Files
If JDK is in C:\Program Files (X86)