linux下安裝oracle jdk

centos7 安裝oracle jdk8

①centos7 自帶了open jdk7。是以這裡首先移除自帶的jdk：

yum remove java-1.7.0-openjdk

②安裝oracle jdk：

cd /usr/local/jdk1.8.0_111

alternatives –install /usr/bin/java java /usr/local/jdk1.8.0_111/bin/java 2

alternatives –config java

（選擇oracle jdk對應的數字）

alternatives –install /usr/bin/jar jar /usr/local/jdk1.8.0_111/bin/jar 2

alternatives –install /usr/bin/javac javac /usr/local/jdk1.8.0_111/bin/javac 2

alternatives –set jar /usr/local/jdk1.8.0_111/bin/jar

alternatives –set javac /usr/local/jdk1.8.0_111/bin/javac

③添加環境變量：

vim /etc/profile

export JAVA_HOME=/usr/local/jdk1.8.0_111

export PATH=PATH:JAVA_HOME/bin:$JAVA_HOME/jre/bin

ubuntu1604下安裝jdk8

也可以跟上面一樣，直接在/etc/profile下配置JAVA_HOME