下载jdk:http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
解压:
sudo mkdir /usr/lib/jvm
sudo tar zxvf /home/用户名/Downloads/jdk-8u25-linux-i586.tar.gz -C /usr/lib/jvm
sudo gedit /etc/profile
#set java environment
export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_25
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH
保存退出,输入以下命令使之立即生效。
配置默认JDK:
sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_25/bin/java 300
sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8.0_25/bin/javac 300
//后面两项可以不配置
sudo update-alternatives --install /usr/bin/javah javah /usr/lib/jvm/jdk1.8.0_25/bin/javah 300
sudo update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.8.0_25/bin/jar 300
//版本切换命令
sudo update-alternatives --config java
sudo update-alternatives --config javac
测试
java -version
javac -version