Ubuntu 18.04安装Java JDK8三种方式

1/

sudo apt-get update

sudo apt-get install openjdk-8-jdk

java -version

 

2/

sudo apt-get install python-software-properties

sudo add-apt-repository ppa:webupd8team/java

sudo apt-get update

sudo apt-get install oracle-java8-installer

java -version

 

3/

sudo mkdir /usr/lib/jvm

 

sudo tar -zxvf jdk-7u60-linux-x64.gz -C /usr/lib/jvm

sudo vi ~/.bashrc

export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_191  ## 这里要注意目录要换成自己解压的jdk 目录
export JRE_HOME=${JAVA_HOME}/jre  
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib  
export PATH=${JAVA_HOME}/bin:$PATH

source ~/.bashrc

sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_191/bin/java 300

java -version

sudo update-alternatives –config java  （多个java版本切换）