Linux 笔记 #02# Installing MySQL & Installing the Default JRE/JDK

Environment: debian 8

Installing MySQL

Reference material: https://linode.com/docs/databases/mysql/how-to-install-mysql-on-debian-8/

sudo apt-get install mysql-server
sudo mysql_secure_installation # 进行一些初始化设置
mysql -u root -p 

Installing the Default JRE/JDK

Reference material: https://www.digitalocean.com/community/tutorials/how-to-install-java-with-apt-get-on-debian-8

1. Installing the Default JRE/JDK：

sudo apt-get update
sudo apt-get install default-jre
sudo apt-get install default-jdk

2. Managing Java：

sudo update-alternatives --config java # 同时可以看到 Java 被安装的位置

3. Setting the JAVA_HOME Environment Variable：

root@i:~# sudo update-alternatives --config java
There is only one alternative in link group java (providing /usr/bin/java): /usr/lib/jvm/java--openjdk-amd64/jre/bin/java # copy this Path!
Nothing to configure.
root@i:~# sudo vim /etc/environment
root@i:~# source /etc/environment # reload
root@i:~# echo $JAVA_HOME
/usr/lib/jvm/java--openjdk-amd64/jre/bin/java

Contents of  /etc/environment :

JAVA_HOME="/usr/lib/jvm/java-8-oracle" # your own copied path

ps. apt-get install 的默认安装目录

     .下载的软件存放位置
       /var/cache/apt/archives

     .安装后软件默认位置
    /usr/share

     .可执行文件位置
    /usr/bin

     .配置文件位置
     /etc

    .lib文件位置
   /usr/lib 

-------- by **** 流火j