I want to call java from python with Py4J library,
from py4j.java_gateway import JavaGateway
gateway = JavaGateway() # connect to the JVM
gateway.jvm.java.lang.System.out.println('Hello World!')
I've got the following error: "Py4JNetworkError: An error occurred while trying to connect to the Java server". It's seems that no JVM is running, how to fix that?