Nacos启动报错解决：which: no javac in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin)

 which: no javac in (/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64//bin:/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64//jre/bin:/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64//bin:/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64//jre/bin:/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64/jre/bin/java/bin:/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64/jre/bin/java/jre/bin:/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64/jre/bin/java/bin:/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64/jre/bin/java/jre/bin:/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64//bin:/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64//jre/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin)
 readlink: missing operand
 Try 'readlink --help' for more information.
 dirname: missing operand
 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! !!

问题原因分析

1. java环境未设置
2. nacos 对应java_home路径

核心还是java_home路径未设置正确

解决方法

1. 配置环境

 [root@localhost ~]# which java   //找到jdk位置
 /usr/bin/java
 ​
 [root@localhost ~]# ll /usr/bin/java 
 lrwxrwxrwx. 1 root root 22 2月  24 12:26 /usr/bin/java -> /etc/alternatives/java
 ​
 [root@localhost ~]# ll /etc/alternatives/java
 lrwxrwxrwx. 1 root root 73 2月  24 12:26 /etc/alternatives/java -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64/jre/bin/java
 ​
 [root@localhost ~]# ll /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64/
 ​
 [root@centos7-2 nacos]# vi /etc/profile
 # 在最后增加
 export JAVA_HOME=/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64/          
 export JRE_HOME=$JAVA_HOME/jre
 export CLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
 export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH
 [root@localhost ~]# source /etc/profile
 ​

2. 测试启动

依然报错！！！

后来查看nacos startup.sh

 [ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=$HOME/jdk/java
 [ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=/usr/java
 [ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=/opt/taobao/java
 [ ! -e "$JAVA_HOME/bin/java" ] && unset JAVA_HOME

对比第一步的java地址

 [root@localhost ~]# ll /etc/alternatives/java
 lrwxrwxrwx. 1 root root 73 2月  24 12:26 /etc/alternatives/java -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64/jre/bin/java

很明显缺了一个jre

 export JAVA_HOME=/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64/jre          
 export JRE_HOME=$JAVA_HOME/jre
 export CLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
 export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH

解决

 [root@iZ2zei0t9v2ixxdu451s8jZ bin]# sh startup.sh -m standalone
 /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64/jre/bin/java -Djava.ext.dirs=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64/jre/jre/lib/ext:/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64/jre/lib/ext  -Xms512m -Xmx512m -Xmn256m -Dnacos.standalone=true -Dnacos.member.list= -Xloggc:/usr/local/nacos/nacos/logs/nacos_gc.log -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M -Dloader.path=/usr/local/nacos/nacos/plugins/health,/usr/local/nacos/nacos/plugins/cmdb -Dnacos.home=/usr/local/nacos/nacos -jar /usr/local/nacos/nacos/target/nacos-server.jar  --spring.config.additional-location=file:/usr/local/nacos/nacos/conf/ --logging.config=/usr/local/nacos/nacos/conf/nacos-logback.xml --server.max-http-header-size=524288
 nacos is starting with standalone
 nacos is starting，you can check the /usr/local/nacos/nacos/logs/start.out