java

安装默认版本

sudo apt install default-jdk

Java 8

sudo apt install openjdk-8-jdk

which java

root@356ca11f70aa:/usr/local# which java
/usr/bin/java
root@356ca11f70aa:/usr/local# ls /usr/bin/java
/usr/bin/java
root@356ca11f70aa:/usr/local# ls -l /usr/bin/java
lrwxrwxrwx 1 root root 22 Mar 19 05:13 /usr/bin/java -> /etc/alternatives/java
root@356ca11f70aa:/usr/local# ls -l /etc/alternatives/java
lrwxrwxrwx 1 root root 43 Mar 19 05:13 /etc/alternatives/java -> /usr/lib/jvm/java-11-openjdk-amd64/bin/java
root@356ca11f70aa:/usr/local# ls -l /usr/lib/jvm/java-11-openjdk-amd64/bin/java
-rwxr-xr-x 1 root root 10304 Jan 15 15:14 /usr/lib/jvm/java-11-openjdk-amd64/bin/java
root@356ca11f70aa:/usr/local# cd /usr/lib/jvm/java-11-openjdk-amd64
root@356ca11f70aa:/usr/lib/jvm/java-11-openjdk-amd64# ls
bin  conf  docs  include  jmods  legal  lib  man  release

配置环境变量

vim /etc/profile

在最后面添加

export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64
export PATH=$PATH:$JAVA_HOME/bin
export CLASSPATH=.:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar

然后更新

source /etc/profile

root@356ca11f70aa:/usr/lib/jvm/java-11-openjdk-amd64# echo $JAVA_HOME     
/usr/lib/jvm/java-11-openjdk-amd64

或者输出版本号

root@356ca11f70aa:/usr/lib/jvm/java-11-openjdk-amd64# java -version
openjdk version "11.0.6" 2020-01-14
OpenJDK Runtime Environment (build 11.0.6+10-post-Ubuntu-1ubuntu118.04.1)
OpenJDK 64-Bit Server VM (build 11.0.6+10-post-Ubuntu-1ubuntu118.04.1, mixed mode, sharing)

编个程序试试

vim test.java

public class test {
        public static void main(String args[]) {
                System.out.println("Hello world!");
        }
}

编译执行

root@356ca11f70aa:~# javac test.java
root@356ca11f70aa:~# java test
Hello world!

tomcat

Tomcat服务器是一个免费的开放源代码的Web应用服务器，属于轻量级应用服务器，在中小型系统和并发访问用户不是很多的场合下被普遍使用，是开发和调试JSP程序的首选。
tomcat官网
我下载好传到docker里

cp apache-tomcat-8.5.53.tar.gz /usr/local/

解压

tar -zxvf apache-tomcat-8.5.53.tar.gz

赋权限

chmod 755 -R apache-tomcat-8.5.53

修改启动脚本，进入tomcat的bin目录下

vi startup.sh

在最后一句前加上如下

#set java environment
export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:%{JAVA_HOME}/lib:%{JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH

#tomcat
export TOMCAT_HOME=/usr/local/apache-tomcat-8.5.53

运行

./startup.sh

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