安装py4j

    pip install py4j

因为我的python环境是anaconda3/envs/sdd_py36，所以安装以后
py4j 的python库的位置是/anaconda3/envs/sdd_py36/lib/python3.6/site-packages/
py4j的java库的位置是/anaconda3/envs/sdd_py36/share/py4j/py4j0.10.8.1.jar

$ python

>>> from py4j.java_gateway import *                             
>>> port = launch_gateway()                                     
>>> gateway = JavaGateway(
... gateway_parameters=GatewayParameters(port=port),
... callback_server_parameters=CallbackServerParameters(port=0))
>>> random=gateway.jvm.java.util.Random()
>>> number1=random.nextInt(10)
>>> number2=random.nextInt(10)
>>> print(number1,number2)
2 3

可能会遇到的错误：
error: illegal character: '\u3000'
错误原因：中文全角空格

参考：
Getting Started with Py4J
在python里调用java的py4j的使用方法
error error: illegal character: ‘\u3000’
Py4J_Advanced Topics