阿里云Ubuntu服务器安装JDK

安装 JDK

1. 官网地址
   https://www.oracle.com/java/technologies/javase-jdk13-downloads.html

2. 下载安装包
   自己想办法下载吧，我是通过 git 传过去的...

3. 解压 jdk
   tar -xzf jdk-13.0.2_linux-x64_bin.tar_2.gz

4. 移动到目录 /usr/lib/jvm/ 中

   sudo mkdir /usr/lib/jvm
   sudo mv jdk-13.0.2 /usr/lib/jvm/
   

5. 配置环境变量, 编辑文件 /etc/profile, 在末尾添加
   vi /etc/profile

   # jdk config
   export JAVA_HOME=/usr/lib/jvm/jdk-13.0.2
   export JRE_HOME=${JAVA_HOME}/jre
   export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
   export PATH={JAVA_HOME}/bin:$PATH
   

6. 使环境变量生效
   source /etc/profile

7. 配置jdk

   sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk-13.0.2/bin/java 300
   sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk-13.0.2/bin/javac 300
   sudo update-alternatives --install /usr/bin/javap javap /usr/lib/jvm/jdk-13.0.2/bin/javap 300 
   sudo update-alternatives --install /usr/bin/javadoc javadoc /usr/lib/jvm/jdk-13.0.2/bin/javafoc 300
   

8. 安装成功
   java -version