Ubuntu安装java8

1.在官网上下载JAVA8，下面是路径，请选择跟系统匹配的版本，我下载的是jdk-8u131-linux-x64.tar.gz。

http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

2.新建java安装目录

sudo mkdir /usr/local/liko/java

3.移动jdk-8u131-linux-x64.tar.gz 到 /usr/local/liko/java

sudo cp /home/liko/download/jdk-8u131-linux-x64.tar.gz /usr/local/liko/java

解压

tar zvxf jdk-8u131-linux-x64.tar.gz 5.删除安装文件 rm jdk-8u131-linux-x64.tar.gz

6.配置环境变量

sudo gedit ~/.bashrc

在文件末尾添加如下文件

export JAVA_HOME=/usr/local/liko/java/jdk1.8.0_25 export JRE_HOME=${JAVA_HOME}/jre export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib export PATH=${JAVA_HOME}/bin:$PATH

7.配置默认JDK版本

sudo update-alternatives --install /usr/bin/java java /usr/local/liko/java/jdk1.8.0_25/bin/java 300 sudo update-alternatives --install /usr/bin/javac javac /usr/local/liko/java/jdk1.8.0_25/bin/javac 300 sudo update-alternatives --install /usr/bin/jar jar /usr/local/liko/java/jdk1.8.0_25/bin/jar 300

检查

sudo update-alternatives –config java

8.验证

java -version