先更新镜像源文件卸载java

tomcat下载地址
https://mirrors.tuna.tsinghua.edu.cn/apache/tomcat/tomcat-8/v8.5.83/bin/apache-tomcat-8.5.83.tar.gz

jdk下载地址
https://www.oracle.com/java/technologies/downloads/#java8

卸载java

apt-cache search java | awk '{print($1)}' | grep -E -e '^(ia32-)?(sun|oracle)-java' -e '^openjdk-' -e '^icedtea' -e '^(default|gcj)-j(re|dk)' -e '^gcj-(.*)-j(re|dk)' -e 'java-common' | xargs sudo apt-get -y remove

清除配置信息:

dpkg -l | grep ^rc | awk '{print($2)}' | xargs sudo apt-get -y purge

清除java配置及缓存:

bash -c 'ls -d /home/*/.java' | xargs sudo rm -rf

手动清除JVMs:

rm -rf /usr/lib/jvm/*

安装java

sudo apt install openjdk-8-jdk

查看java版本

java -version

配置java变量

sudo vim /etc/profile

插入

export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
export JRE_HOME=$JAVA_HOME/jre
export CLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH

配置文件立即生效

source /etc/profile

解压文件

sudo  tar -zxvf apache-tomcat-8.5.72.tar.gz

给予文件权限

sudo chmod 755 -R apache-tomcat-8.5.

修改Tomcat配置变量

cd /usr/local/tomcat/apache-tomcat-8.5.72/bin

进入

sudo  gedit  startup.sh

尾部插入
#tomcat

export JAVA_HOME=/usr/local/jvm/jdk1.8.0_351
export TOMCAT_HOME=/usr/local/tomcat8/tomcat8/
export CATALINA_HOME=/usr/local/tomcat8/tomcat8
export CLASS_PATH=$JAVA_HOME/bin/lib:$JAVA_HOME/jre/lib:$JAVA_HOME/lib/tool.jar
export PATH=$PATH:/usr/local/jvm/jdk1.8.0_351/bin:/usr/local/tomcat8/tomcat8/bin