Nacos 启动常见错误

╰半夏微凉° 2023-09-27 19:26 33阅读 0赞

## **1. Could not find or load main class** ##

> Error: Could not find or load main class  
> Caused by: java.lang.ClassNotFoundException:

**解决办法：**  
x JAVA\_OPT\_EXT\_FIX="-Djava.ext.dirs=$\{JAVA\_HOME\}/jre/lib/ext:$\{JAVA\_HOME\}/lib/ext"  
√ JAVA\_OPT="$\{JAVA\_OPT\} -Djava.ext.dirs=$\{JAVA\_HOME\}/jre/lib/ext:$\{JAVA\_HOME\}/lib/ext"  
x echo "$JAVA $JAVA\_OPT\_EXT\_FIX $\{JAVA\_OPT\}"  
√ echo "$JAVA $\{JAVA\_OPT\}"  
x echo "$JAVA $JAVA\_OPT\_EXT\_FIX $\{JAVA\_OPT\}" > $\{BASE\_DIR\}/logs/start.out 2>&1 &  
x nohup "$JAVA" "$JAVA\_OPT\_EXT\_FIX" $\{JAVA\_OPT\} nacos.nacos >> $\{BASE\_DIR\}/logs/start.out 2>&1 &  
√ echo "$JAVA $\{JAVA\_OPT\}" > $\{BASE\_DIR\}/logs/start.out 2>&1 &  
√ nohup $JAVA $\{JAVA\_OPT\} nacos.nacos >> $\{BASE\_DIR\}/logs/start.out 2>&1 &

## **2. Please set the JAVA\_HOME variable in your environment** ##

> which: no javac in (/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! !!

**查找原因：**  
输入echo $JAVA\_HOME结果为空，说明没有配置java环境变量

**解决办法：**  
配置JAVA环境变量

### **2.1 找到jdk安装路径** ###

[root@localhost bin]# ls -lrt /usr/bin/java
    lrwxrwxrwx 1 root root 22 Mar 15 09:59 /usr/bin/java -> /etc/alternatives/java
    [root@localhost bin]# ls -lrt /etc/alternatives/java
    lrwxrwxrwx 1 root root 73 Mar 15 09:59 /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 bin]# cd /usr/lib/jvm
    [root@localhost jvm]# ll
    total 4
    drwxr-xr-x 3 root root 4096 Mar 15 09:59 java-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64
    lrwxrwxrwx 1 root root   21 Mar 15 09:59 jre -> /etc/alternatives/jre
    lrwxrwxrwx 1 root root   27 Mar 15 09:59 jre-1.8.0 -> /etc/alternatives/jre_1.8.0
    lrwxrwxrwx 1 root root   35 Mar 15 09:59 jre-1.8.0-openjdk -> /etc/alternatives/jre_1.8.0_openjdk
    lrwxrwxrwx 1 root root   51 Mar 15 09:59 jre-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64 -> java-1.8.0-openjdk-1.8.0.242.b08-0.el7_7.x86_64/jre
    lrwxrwxrwx 1 root root   29 Mar 15 09:59 jre-openjdk -> /etc/alternatives/jre_openjdk

### **2.2 在/etc/profile文件下添加以下代码并执行** ###

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