【异常信息】
sudo ./startup.sh
which: no javac in (/sbin:/bin:/usr/sbin:/usr/bin)
readlink: 缺少操作数
Try 'readlink --help' for more information.
dirname: 缺少操作数
Try 'dirname --help' for more information.
ERROR: Please set the JAVA_HOME variable in your environment, We need java(x64)! jdk8 or later is better! !!

【Java环境】
[root@192 jarboot]# java -version
java version "1.8.0_202"
Java(TM) SE Runtime Environment (build 1.8.0_202-b08)
Java HotSpot(TM) 64-Bit Server VM (build 25.202-b08, mixed mode)